Question about non-cash donations

[Cyryl]

I recently went through a small box of donations for our parish and found some old British Sovereigns and silver Crowns. I thought it’d be easy to log them as standard currency at first, but the face value is nothing compared to the gold and silver weight. Our vault’s been a bit humid lately too, so I noticed some spots on the Victorian pieces which is worrying for the preservation. I’ve been trying to find the British coins value online to get things sorted, but I’m honestly a bit lost with all the different mint marks and conditions. I really want to make sure I record the "fair market value" in PowerChurch for the donor's receipt without making any big mistakes. Has anyone here dealt with valuing a numismatic collection like this for church records before? I'd appreciate seeing how you guys handled the appraisal part.