Vintage handles may be a joy to find and are wonderful models for use as templates but I'd be leery of installing one as a user unless it was NOS in origin and appearance. To me 'previously enjoyed' handles are best suited for wall hanger displays. Lots of nefarious and subtle 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 ultimately broke due to grain runout but had increasingly become compromised by internal deterioration.
PS: "Beauty" handle, by the way, JB and I'm glad you saved it. The above caution does apply and I don't see any reason why a talented lad like yourself, quinton or COTS or somebody else couldn't model a new haft directly off this one.