Hi Matt,
As you already noticed, I'm based in france, so if you're looking for some parts which won't be available in your country, probably the best way to find them is France.
These days I begin to restorate a 63' Panhard PL17 which is a French air-cooled flat-twin sedan. So I've got many contacts in calssic cars here in France, just missed to buy a Simca van 2 years ago.