I've been in this sport a long time, and have never heard a lock called a roller lock, that wasn't built by our own Bob Roller. I've heard the term roller frizzen used to dicribe a frizzen that either has its own roller, or rolls on one attached to the frizzen spring. I own a Lehigh antique smooth rifle that has a roller on the end of the mainspring, and through all the research, and conversations with knowledgeable collectors, and restorers, nobody ever called it a roller lock. My guess would be that when this lock is removed it will have Bob's mark in it.
Hungry Horse