Well, thanks for the responses! I feel much better now. When I felt like I hit a stone wall, I congratulated the manager for winning, as a cheapo seat cover was not worth pursuing further. I said I would turn to social media, which he said was a threat. It really wasn't, as I had every intention of actually doing just that...making it a statement instead of a threat.
Anyway, I closed the file and moved on to to other things. Then, out of the blue they offered to replace my missing mirror (with a used one, of course), and offered a $250 bidding credit. After hearing all your experiences, I think I made out pretty good.
It was more the principal than anything else. Over the last year I won a Stearman airplane that turned out to be missing half the tail, a hood for the hummer, that wound up being damaged and coated with bed liner (unusable to me and more work to remove the bed liner than the cost of the hood)...and then I won this HMV, which came missing a mirror, a blue seat, a non HMV battery, and a few other little issues that were not disclosed. In short, this was more principal than monetary. I reached a point where I was just plain tired of Iron Planet shorting me every exchange.
I got the HMV 5 weeks ago...still waiting on the SF97. I agree...it'll be nice to be done with IP for a while!