OOP, never canon, but oddly enough not Unseen.
Minis are always "seeable". Art was only ever the problem. However, for consistency, CGL elects not to use any art not developed in-house, and not to use minis based on the unseen art in their official works (books, games, etc). You're welcome to post images of any minis you own (barring a few restrictions around illegal/garage copies).
The MFUK minis were more or less only ever kitbashed combinations of mini parts (although David McCulloch, aka MacAttack, did draw a few up from the minis, IIRC). So there's no art problem per se. Ral Partha Europe decided to pull them from production last year, so it's not a big issue any more.
W.