I spent alot of time looking for a 2nd gen Camaro about one year ago and purchased a 71 RS/SS 396 big block car with all the paperwork to verify its pedigree for $24K, 100% original. The car you mention has been modified greatly so the SS designation should be of little consequence, IMO, when making an offer to the owner. The 2nd gen Camaro small blocks which do have inherent value are the Z/28 cars, especially the 1970.5 due to factory high HP ratings and high compression engines.
Having said that, it does look like a clean car and well cared for. The values have risen in the past year thanks to the 1st gen Camaros. I would guesstimate $11-$14K for a fair deal. Good luck with the hunt!
