Well, Keith - knowing what country you live in would have been a great help. But, I did some backtracking to find out where the Ideal Home Exhibition
(IHE) is held - and this might help you find a replacement (especially if you live in the UK). The exhibitor for Woll cookware at the IHE in Glasgow last year was Proven Products Limited of Nottingham, England. PPL has a page listing replacement Woll Safety Glass Lids
that might have what you are looking for.
If you don't live in the UK - you still might try sending them an email on their Contact Page
and see if they can put you in touch with a source where you live since they are a Woll distributor.