I believe it's the 41R-539. Looking at a copy of a 4053 parts breakdown 'Holley Carburetion Variable Specifications And Parts' with part numbers that I have had since 1974 indicates (136)41R-539. Exploded view shows fast idle cam like what Everette's part number shows, but that not what is on a 4053. The one on the ebay auction may be green, but is more like what's on the OEM carbs.
Here is a pic of one.