It sounds like you have everything but the drawing.
Unfortunately, I don't know of any detailed drawings of flintlocks that are available although I must confess I didn't spend much time doing a web search.
A possible idea that might work is for you to order the Track of the Wolf catalog.
In it are photos of the locks they sell but the important thing is the photos are actual size and they show both the inside and the outside of the lock.
Examples of these photos can be seen in these links:
http://www.trackofthewolf.com/Categories/PartDetail.aspx/722/1/LOCK-SS-FK-RH
http://www.trackofthewolf.com/List/Item.aspx/726/1
The tumbler which carries the half **** notch, the full **** notch and the spur that the mainspring reacts against is usually a bit hard to see because it is partially covered by the bridle (bridge that supports the tumbler axle or pivot pin).
On the plus side, on page 170 of my Catalog 17 there is a good view of the individual Siler lock parts shown full size.
The picture even includes the mainspring in its relaxed state.
I'm sure the newer catalogs will have the same photos in them.
Armed with the full size photos you could measure the various parts, the screw locations etc and develop your own plans.
That would be far better than to just start sketching something up without knowing the relationship between the parts.
Although the locks represented by the pictures may not be small enough for your pistol, after knowing the relative sizes of the parts and their locations it could be scaled down by some factor like 0.9.
About the only thing that cannot be measured from these photos is the thickness of the parts.
To give an idea of what these thicknesses are, on a large Siler the tumbler body (where the full **** notch is) is .240". The bridle that fits over the tumbler to support it clears the tumbler body by about .010".
The mainspring is about .400 wide at the "U" bend and tapers to about .300 where the end contacts the tumbler mainspring spur.
The lockplate is generally about 0.165" thick except at the bolster at the top that the mainspring reacts against. This area of the lockplate is about .300" thick.
A link to the TOTW site where the catalog can be ordered:
http://www.trackofthewolf.com/Categories/PartDetail.aspx/303/1/CATALOG-18