1985 is newer than 1982, when
Lewmar came out with new
winches. The OP
winches look like pre 1982. But maybe there is a old
winch drum on a shelf for 30 years no one has thought to look for.
It's quite possible that a
winch drum, if one could be located, won't fit. One these old winches they didn't always make the parts interchangeable. Stuff like pawls, springs, bearings, circlips, etc. would all be the same. But the final machining of the castings would be done custom for each winch to make everything fit correctly. They didn't have the accuracy of modern CNC mills back then. Those holes for the pawls were probably done by "hand" after the spindle and drum were already mated.