A quick follow up. I've spoken to my pal who fabric covered an M Type MG for me a couple of years back. He's done 20(?) fabric bodied cars over the years. He always uses 'Sheet wadding' from Woolies. Apparently it's about 1/4" in thickness but compresses to almost nothing when the job is done. I was *very* happy with the M Type when he had finished..

hth...

Edit: Here it is..

http://www.woolies-trim.co.uk/p-1548-wadding.aspx

Location: Cambridge

Thank you Hugh, I have decided to go down the wadding route from Woolies as you suggest.
Cheers,
Dave.

Location: Sheffield

I agree with Hugh Barnes. Foam will almost certainly give that "puffed-up" look. I have covered a few fabric bodies and always used the cotton wadding. The covering job is best done on a warm, sunny day, when the fabric will be more flexible. A hint from experience - make sure there are no projecting nail heads. The wadding may hide them at first but they will appear again when everything settles down.