Vintage handles may be a joy to find and are wonderful models to use as templates but I'd be leery of installing one on a user unless it was NOS in appearance. To me 'previously enjoyed' handles are best suited for wall hanger displays. Lots of nefarious things happen to wood (wood borers of course are obvious) as it ages in exposed environments; internal dry rot and fungal growth come to mind. Varnished, coated or sealed wood for instance can no longer breathe which has it's own long term implications that even include damage via frost action.
Below is a cross section of a handle that broke and had been compromised by internal deterioration beforehand.