I've had a look at the Omega bits as a possible donor.

Starting at the back, the differential is quite large but useable. The rear hubs are part of the trailing arm and so it would be necessary to make up a new bearing carrier to take the Omega bearings.

The gearbox and engine are quite large but not so big that they would be unusable, using similar modifications to the MT75 details in the announcements section.

Up front the hubs are "rear stearers" i.e the steering arms face backwards, not forward like the Sierra/BMW ones. This puts the steering rack where the sump needs to be. This might be solvable by swaping the front uprights side-for-side, but I would have to do some work to make sure good geometry can be maintained.

If anyone fancies trying to use this donor I'd help where I could as this will help me with future editions of the book.

Cheers

Chris