Greetings, I have not found a Constantinian Dynasty folles/nummus that was this completely silvered. I have several of the Tetrarchy issues that are fully silvered but few of these it looks like an Antoninianus. AH didn’t list the reference but I believe it to be Treveri RIC VI 870 ~310 at an early type hefty 5g/24mm: I’ve been lazy with the macro photography so apologies for the cell phone pics. Love to see your silvered Constantine era coins.
Here is a Constantine II silvered follis that has a lot of the coating left. Silvered Centenionalis of Constantine II, Obverse: CONSTANTINNVS IVN NOB C “Constantine Junior noble caesar” Reverse: PROVIDENTIRE CAESS SMHє “To the providence of the two caesars.” camp gate, two turrets, eight layers, star above I am sure that your piece has the original silvering, but I could be wrong since I am not an expert in this area. This Constantine follis has traces of silvering.
It is possible that this was resilvered in more modern times. I know that some collectors chemically resilvered coins in the late 1800s. I have the following example that I suspect was also resilvered in more modern times.
You may be right. Naville 80 had several fully silvered Constantine’s, perhaps also in the less than ancient camp. https://www.biddr.com/auctions/navillenumismatics/browse?a=3401&l=3894142 https://www.biddr.com/auctions/navillenumismatics/browse?a=3401&l=3894142
