When I opened your jewelry estimate page, “A close-up of any stamps helps” was tucked into the upload instructions. I'd make that a separate photo prompt: one whole-piece shot, then a hallmark close-up. That gives people a clearer way to use the three-photo allowance, especially when they don't know what affects resale value.
I make ThreadFox. I went through your jewelry tool as a first-time visitor and wrote up what I hit; the full check is free:
https://threadfox.vip/p/what-s-your-jewel…
Does the estimate distinguish an unreadable hallmark from a piece with no hallmark?