A few things come to mind reading through these posts that hopefully help some newer people out:
-Just buy a scrap block of maple to practice on, clamp it in a vise and inlet the heck out of it. Call up wherever you by your ML parts from and ask for a scrap block of maple for inlet practice. Inletting is the single most important skill to have going into a build, everything is inletting something into wood so make sure you are dialed in with practice and understand how to sharpen your chisels before you start a build.
-Create a pattern out of paper and glue it with some wood glue to a sheet of whatever metal you're using. It just has to hold good enough to saw out and then it gets burned off in the first annealing. The advantage to a paper pattern is it is easy to bend around and fit to the rifle to get the exact shape and proportions you want before cutting it out of brass or whatever you're using. If you can acquire tracings of originals or shapes you want to incorporate into other builds then cut the pattern out of card board and save them in an altoids can or something and just transfer those to the paper.
-The purpose of the draft is to clean up the outside of the part, and also for when you're tracing it on the wood with an exacto knife that the cut line is just slightly inside the actual border of the part. This way you can slowly walk the part in and up to the actual border without your cuts going outside it. It also acts as a cork in that the deeper it goes the tighter it gets. You don't need much of a draft but it is crucial on just about everything you inlet.
-The purpose of that exacto knife outline is to act as a guide to follow up with a series of stabbing cuts straight down with your chisels and gouges that deepen it and create a border to prevent chip out. This part is a little tricky to get the hang of because you will encounter complex curves that none of your gouge profiles will match, you can get either a very very narrow chisel or a narrow shallow gouge (a #4 for example) and follow any curve with practice and have it one tight flowing line. You have to rock it back and forth inside the xacto cut always keeping the tail of the chisel or gouge inside the cut line to keep a consistent line and bend the stab with your wrist as you rock it to follow the curves. It's difficult to explain in text but sort of think of the center of the tool as a fulcrum point that you are rocking back and forth to draw a line that flows around the curve. Some experienced builders will create this border entirely with an xacto knife but newer builders will tend to just make mushy blown out inlets with just an exacto knife and not using the chisel stabbings. Furthermore, chasing an xacto cut with a chisel stab is great practice for other things as well.
-The key to consistency is that you return the part to the exact same spot on the rifle every time you go to get a transfer marking. Any slight deviation will cause sloppy inlets. For most things you're inletting, you drill ideally two of the final holes for the part and use sacrificial screws or tacks to return the part to the exact same spot for the initial xacto tracing and every time you return the part to get a transfer reading. Don't drive them in all the way, just enough to hold the part firmly against the wood.
-You need to be able to read your transfer markings, this is another area where practice comes in handy. Markings will transfer to the wood where the part is fitting perfectly and to where wood needs to be removed. A common example of this is if you have marking all around the edge of the inlet and only some at the bottom on the inlet, remove the little bit from the bottom and leave the edge alone, get another marking and wait till you can not see any marking on the bottom before considering the sides of the inlet. Every scenario is different but this is just an example, learn what the marking compound is telling you.
-It's hard to tell but the tacks from the picture look like generic hardware store tacks? You should make your own tacks, it's easy and looks better. 1/16 brass pin stock, clip off a very tiny bit of it, vise it up, file a sharp tip on one side and peen a flat head on the other side. They'll clean up a lot nicer and look better. It doesn't take much to drive them, gentle taps on the head with the ball side of a ball peen to try to avoid divots in the part. One thing every builder should have is a hand vise, get a vintage one off ebay for 25 bucks or get lucky and find one at a flea market. They are amazingly handy for so many different tasks.
-You anneal brass and german silver to soften it up and it will work harden as you tap it in and out of the inlet with a hammer, just go back and anneal it again to soften it back up. This will help it to match the contours of the piece and the brass will work harden out of shape and you have to anneal it to work it back into shape. You can use a small block of scrap hardwood to reduce marring and deformation of the part, which will happen, on everything and will need to get cleaned up in the final part of the build, but try to minimize it early on. The other nice part of annealing brass or german silver is if your inlets get just a little bit sloppy then you can peen them out a little bit to tighten up a problem spot, it won't work as a cure all but it will improve an area you messed up just a slight bit.
- If you do completely blow out an inlet and decide to acraglas it up then make sure you go easy with the dye, try to match it up to the same color of the pre stained wood or even lighter would be better. It will take stain to some degree and you'll avoid those dark miss colored areas. Remember to use the release agent.
-You used far too many tacks for the big inlet, assumedly to hold down areas that were rising up on you. If you look at originals then it's almost always the fewest bare minimum to get a good fit, it's just more appealing to the eye. After you are satisfied with your inletting job, but before you tack it down, you want to very gently and very lightly give the brass part a tiny bend, lengthwise down the center for example but it varies so experiment a little, what this does is as you're pushing down on the part to get an idea about the final fit and where to put the tacks, the part will spring out and grab into the the wood border instead of raising up so much. You have to tweak it a little until it works, gentle bend, push down on it a bit to see how the part will respond to a tack or screw, if if grips the side or springs up in that area, and just keep tweaking it gently until satisfied.
-The purpose of gluing the backside of an inlet is that it creates a wood to metal gasket on things like escucheons and such that will likely never get removed. You will never have glue lines if the part is fit properly. Usually I use titebond 2 for it just for the convenience but I will go the extra step and use a two part epoxy for anything that's going to come in contact with my face.
-The wire inlays you attempted is a completely different animal altogether and should probably be answered in its own thread by hopefully some of the experts here, yeah, good luck with that part, I've got nothin' for ya there.
I think I got most of the high points covered, sorry about the length, this was just going to be a few pointers that spiraled into this and now I'm at point of no return so...Happy Building!