Never bought from him before, but his feedback looks promising. I also note that he has found a large unplayed shop stock from a Chicago shop, all from around the late '60s/early '70s and, as he says, this is one of the pile. I have seen other bits he's had for sale over the past few months - a mixture of top drawer and run-of-the-mill items, but the important thing is that they're all unplayed.
Sure the 45 looks kosher - the ZTSC stamp is in the correct typeface, so no questioning its authenticity there! I would say bid with confidence - there's everything to suggest his reliability.