Very nice work and interesting details.
I question the idea of the tang not rusting, only because I have rehandled a bunch of tang chisels over the years and often find the tang rusted when I remove the original handle. Sometimes just a wee bit, sometimes to the point of almost complete deterioration.
I try to wipe the tang with a thin layer of Tung oil before putting the new handle on. The next person to rehandle it in 50 or 100 years will have to contact my descendants and tell them whether it worked or not.