Robert;
I truly appreciate the info you have supplied on these triggers. I apparently have a different edition of "Two-Shots" than does Researcher as mine gives no info on the triggers at all, only a very brief account of Mr Worrest himself & of course the listing of patents.
The H Lefever on which mine is installed, as mentioned has two SNs. They are however only 4 #s apart @ 73,338 & 73,342. I do not have a current listing of the LAC SN list but in the one I have from a few years ago both of these numbers are the highest listed. Again I have absolutely no proof, but tend to believe this gun is as it left the (Ithaca) factory, likely assembled at the very tail end of production utilizing parts on hand. This is also the only Lefever I have with a two position, non-automatic safety. My earliest one has a two position auto-safe, with all others having the common three position auto-safe. All others are two triggered guns. I do not have one of the Lefever SST's which used the safety button as the selector.