I think these are probably authentic. The seller is an in person grapher -- and if he was a forger he'd be far more likely to post more expensive items, or complete band signed items.
I see your points, but they don’t prove anything either. They could be used the other way. If he meets Rolling Stones/Pink Floyd/Guns’n Roses(as these get listed very often) each week, why not try to get multiple signed items?
I also wonder why a in person collector these days don’t take any proof photos?(Anyway, as far as the listing shows)
if this is a well known reputable IP collector/seller, I rest my case, but I think the questions asked is fair.