Oh... I was going to say something about 'em (b/w ILM unpainted pyro shots). Namely that there are clear differences between the two pyros in your photos. And these relate to another difference I'm seeing in this auction piece. The plates that bisect the intakes. Seems ILM played pretty loose with these on the pyros. This auction piece has at least 3 thick ones, whereas your pyro photos show one model with 3 thick ( upper starboard, lower starboard, lower port - different to the auction model) and one thin, and a second model with at least 3 thin plates. On this last model they're even untrimmed, and stick out beyond the Saturn V can.
Would it be all right if I posted some cropped details from your photos to illustrate what I'm blathering on about here...?