That's a tough one! Rarest: Sig Stat taerdrop strobe. Sig Stat teardrop Flash Ball #384, Dazl-Ray dash light,Sireno 166 Mity Lite, Federal Flash Balls, Whelen Flash Beams, Beacon Ray 17 Federal Enterprises NIB, Red/Blue split domes for both old and newer Beacon Rays, Rota Beam split domes, McDonald ansd Arneson 6V 4 way flasher, JW Speaker Fire Ball, NOS S&W Pancake L11. I picked these because I don't seem to see them out there.
Pictures are on 100 PLUS BEACON post in this section. I guess you guys will have to tell me which are most valuable, and rarest.
Dan