I was riding the bike on a trainer today and I started having knee pain on my right knee. I looked down and asked someone to eyeball it and my knee was behind my pedal spindle. I lowered my seatpost a little and the leg extension is still ok, but the KOPS is still not really on. I think I'm going to hold off on doing anything with this bike and just use it to get around for now...

Thanks for your help though! Vintage trek says that the seatpost should be 27.2mm as people here said.