[Phantomcrow]

Off the top of my head figure that were 3.75 and never made into 6 inch would be--
Old School Captain Britain
Rogue in black with green top
Death Head-- #1 want right here
Quasar -please make a new head
Bombastic Bag Man
Gamora in Armor
Spider man in armor MK 1
Maestro in Armor
Comic Executioner
Comic Yando from classic Guardians
Mr. Negative
Triton
Captain America with split shield

There are quite a few