Fitting an A4 B6 steering wheel to an A6 C5?!

[MikkiJayne]

Don't see many of those about these days

I assume they are physically interchangeable and its just the wiring which is different?

Do you have the same number & colours of wires in the B6 wheel? Could they be cut and spliced on to the C5 plug perhaps? I've done a few swaps like that between various models, although I don't recall having seen inside a B6 wheel.