For a FIAT 500 it is also easy because there are so many cars en Europe. For SEAT 600, our spanish icon, it is not so easy.
But also Porsche parts very hard to find, like the cylinder head of the 944 S2 with four valves, whitch is the same like the left side cylinder bank from V8 928 S4. No way. Also the two parts from magnesium block for the 911 aircooled 2,4S and 2,7 RS. They are all brocken clutchside and a lot of this motors clued (spanish quick repair ,)). Cars for 80.000,- Euracos and more.
So if you like it perfect, may be is hard to have a Vintage car. A lot of cars very bad restored, and they say, this old so what.
Specialy with old Porsche you find 80% Chapuzeros, they have no idea, but you con make a lot of money repairing old Porsches.
Dont buy an old Porsche! The best way to safe money.