Thank you so much - the ID was a huge part of it and I was far from able to do that. I am actually in Canada, and thus Ebay and, I believe, a vendor in New Hampshire would both be close by (though I am guessing that the UK vendor may have certain hard-to-find items that the others may not). When I took off one of the covering plates, the interior was minty clean and I'd like to keep it that way.
I just ended up going with the UK source for an SR2 gasket set; we'd like this thing to last.
Many thanks for all your help; I am sure this is the tip of the iceberg!