I have a '64 type A and have had a similar experience finding parts. Slowly but surely I've managed to get what I need but I haven't gotten to rubber yet. Like yours, all the rubber on mine is rotten.
I saw a '65 in Germany on ebay that just finished auction (
Opel Kadett A Bj.65 + ca. 150 Ersatzteile - (eBay item 220150802907 end time Sep-23-07 09:05:18 PDT)) without meeting reserve.
It's good to know there are other type A's out there, though I still haven't seen another in the US.