Rob,
"BRP" is a brass butt plate. "BTB" is brass hardware on a Trailblazer, Model #27-5 3/4".
Hope this helps, Capt. Chris
_________________________
Capt.Chris Stanaback
RKCC/RKCA Founder
RKS #016
NRA Lifetime Member
CAPTSTANABACK@aol.com
WEBSITE: www.captstanaback.com