Here's some more. I apologize that I can't actually scan these, since I don't own a scanner. I don't know the name of the book these photos came from but it was published in 1994.
Various old props:
Stand-in dolls for the Twin Fairies - apparently the ones used in Ghidrah
The small Kong model for the transport scenes in King Kong Escapes
Mechagodzilla's head. In the back of the head, below the red "ear" you can just make out the switch that was used to turn on the lights in the head.
An old decaying Mothra larva.