Hi folks!
I've been asked to look at some silver and copper cobs, and make an offer on them. I have Sedwick's "Pratical Guide to Cobs," and have been using his site as well as completed auctions on
ebay and at Heritage.
I was hoping to find some more resources for attributing, spotting fakes, and appraising silver cobs, so decided this would be the best place to ask! Here's what I've IDed as a 4 reales Philip II, Mexico, assayer "O." The only way I can attribute this as Philip II is the assayer's mark. While it has some very nice surviving detail, the lack of any date and no inscriptions combine with the cracked planchet to lower the price. I'm thinking of offering $75-$85, and hoping to resell for around $100.

