post images, list out what you have and prices, along with your location might get some local buyers so you don't have to fiddle with shipping
why don't you fix them instead of tearing apart 2 more rare bikes.... look on ebay, the ST90 parts market is flooded right now. the only things worthwhile on that bike are::
GOOD Front fender
GOOD speedometer cable
Blinker stays/blinkers
Air Cleaner Cover
Engine skid plate/down tube
you might get a few bucks for the other stuff on there, but that's the stuff that's in demand. maybe 3 years ago, front fenders were nonexistent
one was without a motor so I tore it down the other I am going to keep together should be easy to get running