I went through the same thing with mine. Two of the three tabs were broken off. I would highly recommend contacting Tony Smith:
Tony Smith
4-5-6 Chevy Trucks
560 South 11th Street
Kansas City, KS 66105
913-207-7789

I got one from him and it is in near perfect condition and for a very reasonable price.

Trey Wilkins
--------
1950 Chevrolet 3100 Five Window
1954 Chevrolet 4100 Dumptruck (Sold)
1957 Chevrolet 6400 Dumptruck
1966 Chevrolet K20 Longbed Fleetside
1966 Chevrolet C60 Grain Truck (Sold)

In the Stovebolt Gallery
More pix on Photobucket