Here's an RSR at Fantasy Junction.
1975 Porsche 911 3.0 Litre RSR
drmatera & kas930 look like the 3.0RS,
I remember going to Fantasy Junction in the mid-90's trying to trade my 930 for a DeTomaso Mangusta. They said they didn't deal in 911's. They must have seen the light, scroll to the bottom.
Fantasy Junction: Brokers of Fine Collector Automobiles and Vintage Race Cars