Last time the bearings were serviced on the hubs and bottom bracket was when? I have seen cone lock nuts loose or near loose on bikes I have picked up, and if don't address it, they can end up being tight (nutted axle vs QR). Having the hubs serviced, with fresh bearings and grease, is trivial in cost if you do it yourself. Make sure lock nuts are tight against the cones (using two cone wrenches, or a cone wrench and a socket on the lock nut). And while you are there, its a good time to do the front wheel and the bottom bracket.

Have you had them serviced since you owned the bike? In 500+ vintage bikes purchased, I have yet to have found a bike yet where the bearings and grease are good. Service work really gets ignored for decades by most owners. I keep hoping I will find one that has been maintained. Its bound to happen, eventually.

Found this in the bottom bracket of a higher end, 1988 Panasonic racing bike I picked up about a month ago: