You'll have to get a grown up to figure it out from the serial number as i have never understood them but from the picture I would say 1990 - 1993.
Does the one you are looking at have the cable holder in the same place? Higher spec Performer if it does or lower spec Performer or Vertigo if its on the top tube.
pretty sure the cable guides on the toptube on the one i was offered, i was thinking performer or vertigo 92-93ish based on what i found having a browse
don't the Pro Freestyle tour bikes also have bent chainstays too as well
i don't think its for me anyway, i'll post a link up to it when he puts it on ebay