I'm hoping someone can help me with this. I'm also hoping it's a simple query.

I have a Linsi vincent steering wheel (Cool name huh) to fit into an 82 Pontiac Firebird and the only steering wheel bosses I have found for it are in the States for about $60.00.
I only paid £20.00 for the wheel so was wondering if anyone knows if another adaptor will fit in it's place.
The centre is a 6 hole ring with a diameter from the centre of one hole to the other is approx 73/74mm across.
Is there anyone in this country than sells them ?
Or would I be better off modifying my own steering wheel boss ?

Thanks in advance.