Yes, the concept does seem to work. And the ability to add shims for different size locks is a very cool idea. I could even imagine using leather in place of the brass being a possibility.
Very kind of you to offer to send me the clamp to try out (my guy is dragging his feet again). I do have a large variety of miquelet locks to try the clamp out. From large musket+ size to the smallest Circassian style. I also have the Italian/Algerian style locks that operate with the toe of the hammer lifting the mainspring UP versus the Spanish style that uses the hammer to push DOWN on the mainspring. But I'm thinking by just reversing the position of the clamp will work with the toe-locks.
I'll send you a PM with my address information. Thanks so much for the opportunity. I'll try it out on different locks and take some photos and report back. Should be an interesting experiment.
By the way, did you remove the sear spring first while the hammer was in the full downward position ?
Yes, they were made in Spain and distributed by CVA back then. Apparently fairly rare to find one now. Here is the ad that was in the CVA catalog back then. I have two of the boot type pistols. One in good used condition, the other in mint, unfired condition. I've never seen one of the full size pistols offered on the market over the last many years. Yes, the quality was very good. At least equal to Pedersoli.