Saw this thread...
Had to post, even if it is old. I have been using the POG OS since 1982, high school. I have collected about 10 over the years and they are all version 1 or 2. One thing I cannot make a connection to on the list is that I have a version 2 with a longer, 2-handed grip. The crossbar is actually about an inch higher in the throat. It has the single green stripe and grommets, but just a naturally longer grip. Still plays the same. I've used pretty much all the versions and I will only play with the version 1 first, or 2 if that is the only available frame when the 1's have broken strings, etc. One poster said the size of the head was a bit different on the earlier frames. I can confirm this. It definitely has more of an "O" shape compared to a typical oval.
15 year HS tennis coach, trying to find perfect blend between old school and new frames.