[C210N]

they were in remarkably good condition...

Antiquity-struck coins would be worth much more than a mere $1700 per ounce.

I wonder how recently they were cast/struck... maybe more recently than thought. Perhaps much much more recent.

[SunkenCiv]

They’re not modern counterfeits, if that’s what you mean.

[seowulf]

I wonder how recently they were cast/struck

Since they're Byzantine sometime between 330 and 1453. I would guess toward the end of that range. You're more likely to stash your gold in a wall when times are unsettled.

[ptsal]

Bkmk