I do not know of a manufacturer that sells bags and racks which are interchangeable with their competition.
Also, the R65 chassis may be a stumbling block as there are but a few bits for this model bike. And some may require a luggage rack to tie 'em all together.
Others have made racks fit with a few new steel straps and some welding. The racks must be secured near the pillion footrest area to prevent flex and failure.
Then there's the whole issue of hard cases and their condition. Some locks are even NLA so if there are no keys, that could be more concerns. Many riders use a wide webbing strap just to insure that the bags don't fly open and send your clothes trailing off behind you. In any case, a swift whack or kick will crack open the older bags, locked or not.
Our Classic Airheads are few compared to new bikes with integrated luggage systems. Limited demand makes it uneconomical to produce old school style cases and the required racks.
Keep an eye on eBay and Internet BMW Riders as racks and luggage sometimes turn up but rarely for R65s.

There's always ballistic fabric bags.