It's very concerning that the seller refuses to reply.
Just to lower the temperature a
bit, this doesn't concern me at all.
Coin dealers with items up for
auction receive countless messages asserting one or another problem with something they are
selling. These messages might relate to ownership ("that's my coin!"), might relate to
provenance ("I feel certain this was dug up yesterday in
Romania!") or might relate to repairs ("it's
tooled!") or authenticity. They also get many questions like "I've a similar coin, what's it worth", and "I have some wheat-ear cents from long ago will you buy them from me". Many of these messages are from completely uninformed people, or even cranks. So when a dealer in genuine coins (who believe he is
selling only genuine coins) gets a generalised message of concern about just one coin he believes genuine from someone completely unknown to him, and the message is probably anyway filtered by secretarial staff, there's a very high chance that no attention is paid to it. That does NOT mean the dealer is deliberately
selling a forgery, in fact it may be
his confidence that stops him replying. I'm sure if a collector or expert known personally or academically to the dealer or if a bunch of different unknown people write in, a different response might result.
Some big name dealers read and respond to each message I send them -
CNG adjusted the description of a coin yesterday on my recommendation. But they know me, and before they knew me, RBW wrote to
CNG and said they should pay attention to my mails. But many dealers, who do not know me personally, don't respond at all to messages I send about mis-described coins. Nowadays, therefore, when
writing to a reputable dealer who doesn't yet know me, I include some credentials ("I've written X and am well-known to Y").
Disreputable dealers are another matter of course. But that doesn't seem to be what we are discussing here, rather an apparently reputable dealer who seems to have made a mistake. It may
help if others write, or if the original messenger writes again so the seller realises it's a serious comment