What is a gas gauge from a 1956 Cadillac worth?

[carguyblack]

Looking to sell a gas gauge of mine and don't know how to determine a fair price to both myself and the buyer.
Is there some sort of antique car parts guide out there?
Chuck

[chrisntam]

Go to eBay, search  "sold" or "completed" listings to see what they sold (or not) for.

Search active listings to see how many are for sale, look at the prices, that'll enlighten you as to the competition.

chris.