Just picked this one up; it's a front loader and at this point I'm not comfortable attempting to open it. Yellow gold plated case is dated L8. I am pretty confident this is a Beau Brummell variant previously unseen/unknown. The case and diamond configuration is the same as the "QQ" , "RR" (yellow) and the "SS" (white), but the face is different. Rather than tiny indents and raised plugs around the perimeter, this one is a "pizza dial" with gold lines on the cream colored dial. My guess is that it is a related double letter variant close to QQ, RR, SS.
This was one of those watches that made me say "wow", when I open the box up. Classic 1950's understated elegance and in excellent presumed unrestored original condition, a few light crystal marks - keeping time.