Looks like he buys and resales collections. Most of these are obtained through the mail. Unless secretarial I would say these are good. Not a big market for forgeries of these celebrities personalized on index cards.
If I am not mistaken I think a couple of these I have seen on jgautographs before. Ones I am familiar with of the old index cards and album pages look like ones i have. I agree with Rick's assessment.
A lot of the cards and album pages I looked at are clearly older ones and when I started collecting back in the 1970s a lot of the minor ones were not very expensive. I was buying Civil War generals for the 10-15 dollar range and actors etc in the 2-10 range. I just cannot believe any forger would have made much money on some of these back then.
I think I've bought from this seller before. Like Rick said, it looks like mostly TTM collections. If you're educated on what you're looking for and watch out for secretarials I think it'll be fine.