VW Parts interchange notes that I have collected. Most this will be for the Super Beetle since that's what we currently have and are working on.
"Here is how to Tell - 1302's have a flat windshields
1303's have a curved windshield
1303's have a different dash to match up with the different windshield, 3 bolt
lower strut mounts
I believe 1975 and later 1303's had rack and pinion steering"
1302 was '71-'72, the 1303 was '73-'79 and the three bolt lower strut mount was
'71 1302 through early '73 1303 there was a mid year change. The front apron
grill was also used on the GSR for the optional oil cooler.
Rear Deck or Engine Cover - 68-79 will interchange but there is a vent difference. A link for rear bonnet pictures and difference can be found at http://web.telia.com/~u31614242/cabrio/rearbonnets.html .
Rear Fenders - rear fenders for 67 to 73 standards & 71 - 72 1302's are the same, rear fenders for 74 to 77 standards & 73 to 79 1303's are the same,
"'74-'79 rear fenders are similar because they have the
large tail light cut out and also a hole for the bumper shock type bracket, but
in '75 they raised the tail lights a bit higher in the fender because of the
bigger bumper."
Front Fenders -" '68-'73 standards are the same, '74-'77 standards are the same, '71 1302 to '73 1303 are the same. '74-'79 1303 are the same".
Rear Apron - "You could fit a '56 deck lid and apron on your Super, if you wanted to. They all interchange also, but of course you'll have to have the correct apron to match the deck lid. "
Doors - Convertible Doors from 70-79.
Most of this info is found at http://www.superbeetlesonly.com/