Hi, I am writing for my 80 year old mom. She has a single blade, bat shaped pocket knife with Babe Ruth's signature and a ball engraved on it. It looks like it may be made of bakelite. The colors are rainbow striped. Her dad got it in the 20's when he played on a miner league team in New York. It was made by Camillus Cutlery but every thing we find seems to be 2 bladed. Does anyone have any ideas on value? Thanks