used on my 1980 vintage was a brand called "Paris Rohan". I'm not sure of the spelling. When it failed I used an off the shelf automotive Delco to get me by until I was able to get a marine style replacement. The only thing I needed to watch out for was the pulley size. The Volvo alternator was driven off the 12 inch fly wheel and the original alternator had a six inch pulley. The replacement came with a three inch pulley. You can see the problem. The alternator would have been in constant over speed so you will have to do the math when you find a replacement.