The chrome is very nice. The set is as new and unused in its original box half of the label is gone so I don't have a part number but application is listed on the half that is still intact see photos.
There is a small paper stating there are special washers if caps are to be used on a Dodge , Plymouth or Studebaker these are NOT present. Also using the label they appear to be pretty universal and look to fit most 5 on 4 1/2" and 5 4 3/4" wheels Ford , Chevy , Olds Pontiac , AMC , Mopar and Mercury. Based on the label these must be from the mid 70's Very cool period piece that would add a cool little extra touch to any car. Take a look at the pictures and I'm sure you will agree. The item "NOS SET Cal Custom Chrome Center Caps For Steel Wheels Hot Rod Rat Kustom Camaro" is in sale since Tuesday, April 28, 2020.
This item is in the category "eBay Motors\Parts & Accessories\Vintage Car & Truck Parts\Wheels, Tires & Hub Caps\Hub Caps & Trim". The seller is "hot-rod-usa-1" and is located in Irvine, California. This item can be shipped worldwide.