Nice walnut Gretsch drum set to play and enjoy... (*note) take a very close look at your RB badge on the bass drum... see how small the vent hole is... well that's not the correct badge type for a RB bass drum... that's a RB snare drum badge... do you mind telling me what your bass drum serial number is? I think your bass drum is actually a early SSB due to the smaller size hole in the RB badge on the bass drum but otherwise a pretty sweet little bop kit.
Sharp eye. Likely someone put a round badge on because the stop sign wouldn't fit with the Pearl mount in that position. If so, probably a factory stop sign kit from day one. Very cool. A lot of Yamaha mounts were used on Gretsch kits eventually.