Alan - try looking through www.tradeexcanada.com and see what you find. I know they won't ship to the US, but another Commonwealth country, I don't know? I've bought a couple guns from them and Anthony is easy to deal with. There are some 10 bore doubles I'm sure. Check both antiques and shotguns as well as some of the other links.

There was another site, www.tradexcanada.com but I didn't look around in it. Might be a nasty site as the url is so close to the real www . trade ex canada . com site.