I don't know how to answer your question about changing the looks of a Hawkin rifle. If you add any kind of sight to the rifle, it will change its look. There are tang peep sites that can be put on these guns, as well as the ghost ring, but each has to be either screwed on, or dove tailed, and both will change the look of the gun.
As to the using only one rod, if you can find a synthetic ramrod, maybe you can get by with only one rod. I prefer having a one piece steel rod, in addition to the rod that goes into the gun. The problem is both strength and length. With the wooden rods that often come from the factory, you have grain runout, that usually results in a failure sooner or later. I have replaced each of my factory rods with hickory rods I have hand picked from a huge selection of rods offered for sale by venders at Friendship. I have not had a failure, but then, I do the hand-over-hand method of running a rod down the barrel, and don't try to grab it at the other end and do it on one stroke. My steel rod is not strong enough to resist being bent with that kind of treatment, so a synthetic rod may be what you want. Check with the major suppliers on the links here. Or someone else will tell you if they are still being made.
As to tools in your possible bag, have both a ball puller jag, and a patch puller jag that is fitted to the thread diamter of the ferral of your rod. If you are shooting a flintlock, by all means get a flintlock tool from TOTW (Track of The Wolf) so you have a good screw driver for tightening and loosening the cockscrew.
If you are shooting a percussion gun( probably) then have a nipple wrench, And a nipple pick. There is a combination tool sold by Thompson that does the trick. You also need an adjustable powder measure- I like the Tedd Cash one with the funnel attached, and the nipple pick in the bottom. I bought mine when Tingle made them. Buy a capping tool, to hold your caps, and make it easier for you to handle them and put them on the nipples. Mine is not kept in the bag, but in a front pants pocket, where I always know where it is.
You need something to hold your lead balls in, and I use a small leather pouch.If you are just going hunting, a bullet block makes more sense, as you won't need a dozen or 2 dozen balls for a hunt, and the block can hold three to five balls that are already put in pre-lubed patches, and either carried in your gab, or hung from your neck with a leather thong. If you used pre-lubed patches, then consider getting a brass or silver " tin " from Tedd Cash to put them in. I also have another such tin that I keep cleaning patches in. Or use a plastic bag to hold the pre-lubed patching when on a range. Its not p/c, but it keeps them clean, and ready. The tins work when you are in a woods walk, or seneca run where you will be judge on the authenticity of what's in your bag. Ditch the plastic bags for that. I bought an antique bottle with a cork stopper to hold my patch lube so I was p/c! I still have it, but it stays mostly in my tackle box, now.
I keep a regular screw driver or two, in my tackle box that always goes with me, in the car, with extras, to check and tighten all the screws on my guns before heading to the firing line or into the field. If a screw is backing out continuously, I use Loctite to stop that. They make a red and blue loctite, now, and one of them allows you to take the screws out without an act of congress, so buy the right kind for your purpose. Or use varnish, or nail polish to make the screws stay put.
On rainy days, or when its hot and humid, I am inclined to take a towel or rag with me to wipe my hands, or the sweat from my eyes, and moisture from my eye glasses.
If you don't prelube patches, and decide to use something other than spit, then you need to carry a bottle or tin of whatever it is you use in the bag, too. Some flintlock shooters carry their priming powder in a small horn in their bags, and not hung from their necks, or kept in a pocket. Most bags come with at least one inside pocket. You may want to sew in more, so that each item has a specific place and you can find it easier. Bulk items, like cleaning patches can be carried loose in the bag, but you might want to stabilize the little items.
Oh, most people need a ball starter of some kind. If you don't make your own, and attach it to your powder horn, or bag strap, then you want to carry that in your bag, too. Mine is carried loose in the bag, as its big enough to recognize by feel, and move out of the way so I can get to my ball bag,and pre-lubed patches.
My flintlock tool is tied with a leather cord, and kept in the front side of my bag, where the flap of the bag allows the cord to pass on the side of it. I always know where it is, even when it is not used that often.
My patch knife is held in a sheath that is part of the strap on my bag, but I have seen others sew a sheath to the backside of their bags for their patch knives, and sometimes for larger knives and hawks.
My best suggestion is to lay out all the things you need to shoot your gun, and make repairs, or to clean it, and remove the lockplate, and or barrel. Then decide which of these tools is a must carry item. Remember, you are not back in 1760 and going to war for a couple of months. You wil probably never be further from your car than an hour's walk, So much of the tools can be kept in the car. At ranges, most provide a bench where you can take your tackle box with these extra tools and components so that they are handy to you at the firing line, too. As you gain experience, you will eliminate more and more things that you carry into the field with you, and that bag will get smaller and smaller, and weigh a lot less.
I can go into the field today without any bag at all and hunt for the day, with a couple of pre-measured powdercharges kept in film cannisters, patches in my pocket, lubed patches and balls in my bullet block, and percussion caps in a capping tool.
