"NTB" stands for a "standard, traditional" Trailblazer handle (i.e. 13 spacers as opposed to a "trapper", Model #25-styled handle), with "nickel silver hardware". "BTB"?? Same description, except "brass" fittings.
Of course: Ya'll know that with nickel silver fittings there is always one brass spacer and with brass fittings here is always one aluminum spacer...Right?? I hope this clears all of the "NTB" and "BTB" coding up. Best for now,
Capt. Chris