I would like to point out that drop and pull have to do with the size of the shooter and geometry. To a large extent, the pull will set the drop. A lot of original guns had a longer pull than I would find comfortable and therefore had more drop than I would find comfortable. I couldn't begin to duplicate many original guns exactly for myself or other modern shooters. Either tall guys were carrying these old guns or they were shooting differently than we do today. Also, I have seen little difference in the measurements of pre-1800 guns and post 1800 guns. More of them seem to have been made for giants than not. You get the right pull and and drop for your shooter and then adjust the two proportionally depending on the type of gun you are making.
Personally, a 13.5" pull with about 3" of drop and a 1/4" of cast off fits me about right and I am a 5' 9" tall. I used to be an inch taller. That is for offhand shooting. My chunk gun was made with 13.25" pull and 2.75" drop and that seem to be Ok for prone. Actually, it could maybe have had a little less drop for prone shooting. If you were shooting from a rest, you might want more drop as I seem to have to scrunch down when I do that. Obviously, how you shoot will also dictate the measurements, and we don't know exactly how the original rifles were shot. We can only guess based on the measurements and assumptions about how tall the original owners were.
As to recoil, I have found that not enough cast-off and too little weight have more to do with felt recoil than anything.