How to Identify collectible glassware from the 1940 s to the 1970 s

The seller is blackpearlvintage and is located in this country US. 4 7/8 (black glass base 4). Fenton burmese hand painted hummingbird vase signed limited edition glass base hand painted burmese glass, limited edition. Hand painted & signed, limited edition #573/2500. The Fenton black glass base is signed with an etched letter F.