I have those on my '72 thanks to the PO. The inside is painted GOLD, as well as the PORSCHE badge in the center cap. The PO clained the center caps were from a 911 - mine look the same as yours. They shine up real nice
The PO of course told me they were VERY desirable and worth lots of $$$$
Can't say I have any more details than what the Cap'n said - they use different lug bolts than stock 914 wheels. With 195/55s on my 15 in. rims, there is NO room for a bigger tire (with stock fenders).