Ford Model A Sedan rear turn signal

This is from a car we sold last year. We coudn't find the turn signal and sold the car as is. The other day while cleaning out my in law's closet, I found it shoved on the top shelf in the back of a closet in a brown paper bag. I've no idea the cost. Have searched online to no avail. I'd like to sell it at some point but I don't want to undersell myself. Any ideas will be great. I believe the mounting bracket is cast iron.