I purchased a used unfinished pistol by a member here. After a lot of work on the stock, drilling a touch hole, modifying the breach plug, installing a front sight, and finish I finally got the gun shooting. Here is the before and after pics.
I picked up two of those Spanish pistols in caplock at a local auction. Mine are both Jukar brand. Those stocks are pretty rough from the factory and the drum to lock fit is poor on mine
Sounds like you had about the same issues. Looks like yours turned out well, good job!