Or would that be a Rossin? Which also has an R on the headtube, the fork crown and the bottom bracket shell has an R drilled out. I bought mine in 1986, but it was NOS; I think that it was probably a 1983. I bought it as a frameset only and had it built up. Interestingly enough, there's no serial number on it that I could see.
Anyway, anything I've read indicates to me that they're a nice enough Italian bike but they don't inspire the reverence that some other marques do. I don't get the impression that they're a highly sought after collector's item.
Canadian connection and relevant to the Marinoni thread: I believe I also read that Marinoni and Rossin worked together in the Poghliaghi factory. Perhaps someone knows more about this and about the bikes in general. They weren't all that common where I come from,but it was a handsome machine and I bought it when I just had to have an Italian bike.