I am a little late posting about this show (better late than never).
It starts this Friday, and is at the The Fairplex in Pomona.

While it is not yet at the level of the old Great Western show, it gets bigger and bigger each year
(I have actually found more hats at this show than the SOS over the past few years).
Also, dealers are more willing to haggle than at the SOS/Max.
(there is also a discounted entry fee for OVMS members, so make sure to bring your card).

Directions/more info here:

West Coast Historical Militaria Collector Show