I converted all of my Famous Covers into Megos. I don't consider most of them customs, since they really did not take any work. But the FC Cyclops outfit cannot easily be adapted to a Mego body. So, I used a doc mego blue suit with yellow trunks and boots. Then I sewed cuffs and those yellow bands around the legs. The belt/harness is from the FC, cut down to fit a Mego body.
FC never made a Prof. X. I shrunk an FC Thor head down to Lion Rock scale, pulled out the hair, filled in the hair plugs with sculpy and mixed fleash color paint to match the tone of the FC head. I found a Mego-ish 6.5 inch body and dressed it in a suit from a maxwell smart figure. The Wheel chair came from a wrestling figure.