Appraisals don't mean squat.
However...if the sucker is super clean, a cool color w/great options, and lots of valid documentation, I don't think $300k is totally out of the question.
Remember, just a couple years ago, HARDTOP six-pack '71s were selling in the $200-250k range. Granted, they're restored, but a 'vert should command at least double a hardtop.
So say $300k, plus $100k for a top-notch restoration. $400k is not that outrageous. Cheaper than what '69 ZL-1s go for.
But regardless, can you get some pics and maybe a shot of the fender tag? Would like to see which one it is in Ola's registry.