I don't think there's one obvious thing in particular, but most reprints are obvious to those that have handle a bunch of them. Thus, my .05 cents advice.......buy some beaters and then loupe them, feel them, take them to dinner, dream of them, smell them, and as some on this board have suggested "take a bath with them." Thus, short of putting T206 cards on your bicycle spokes, you really have to make a commitment before you start taking some chances on high dollar
raw T206 cards.
Hey, just be careful out there, the T206 reprints are getting better and better all the time. As the years have gone on, you can see that some scammers have read this board and picked-up some valuable tips.
For the record the T206 in question is .99% authentic (can't guarantee that extra .01% without the card in-hand and a backlight).
Lovely Day...