I have 2 NASA collectibles, gifted to me by my late uncle who spent 30 years with NASA (Mercury, Gemini, Apollo missions); that can be validated.  I have no doubt they are genuine, he sent them to me as they occurred.  Due to the forgery discussions, I am interested in other experienced opinions.  First Day Cover signed by all three seems to be pretty valuable; I've scanned eBay for years but only recently saw a similar item with all three signatures.  I can post close-up detailed photos if…