I bought a Deerstalker in 2001....The lock was junk right out of the box.I got fed up with it eventually and installed a L&R Drop in replacement..That baby was sparky....eventually took it exclusively on season and killed a fat spike horn with it.A fun gun to shoot.
Just an added note here, I have a RPL lock on my Lyman Great Plains Hawken rifle gun. Had mucho trouble getting it to spark and flash the pan reliably. The not sparking problem was mine not the locks. It is critical to use the correct thickness leather and distance of the flint to the frizzen at 1/2 ####. U get that wrong and 9 chancres out of 10 no spark. This has to do with the geometry of the hammer and flint to the frizzen.
Out of curiosity, what lock from their catalogue did you install? http://www.lr-rpl.com/index.php?option=com_content&view=category&id=38&Itemid=61