I posted my findings on this last year in this thread...
viewtopic.php?f=4&t=32106&p=480872&hili ... ds#p480872
Here's what I posted again for ease.
"The original Palitoy stands differ in three noticeable ways in comparison to the modern stands. The peg shape is different, the semi-circles on the underside rim are positioned differently and the plastic of the modern stands is of a far better quality. You can see the Palitoy ones have a rough, fine bubble like finish in spots. This is true of both the yellow Cantina and clear Death Star stands. There is also a difference in dimensions only detectable with vernier calipers. It's too fractional to detect with the eye, but it is there and haven't found one stand that differs in this way.
Here are some shots to illustrate the points. One other tell about the vintage clear stands is they are often (at least those I have) are a little yellowed. That's not to say that the modern ones won;t yellow with time, so I wouldn't use that as benchmark. Also, I've read that people use the fact that all repros have a circle around the base of the peg. Again this shouldn't be used as a benchmark as some repros, like the one show here, don't have this circle".
In addition to this it's also worth noting that not all the modern/repros have the circle moulding around the base of the peg. So being devoid of this circle isn't a clear indicator of originality.