Found 68 Shelby and need help

[SS427]

I stumbled across a 68 Shelby GT500KR over the holidays in my travels and need a little help and advice. I will give a description with the hopes that some of the more knowledgeable Shelby people can tell me what it may be worth. I was able to convince the seller to let it go but as of right now the seller and I are a LONG ways off on value. He has owned the car for 37 years.

It is a 63B 2+2 Fastback with luxury black interior.
Color is M or White
Trim is 5AA
Build date is mid year 1968
Axle is H or 3.50 Traction loc
Trans is 5 or Toploader 4 speed

The car is completely disassembled, needs quarters, doors, fenders, firewall repair at the pinch welds, outer wheel houses and some floor pan work. Torque boxes are iffy and I was really not able to get underneath the car to see how bad it was but will consider it to be like the topside of the car. Another oddity is it has front side marker lights but no rears but has what appears to be two mounting holes bondo'd closed but no actual side marker opening though I am not sure the 68's used lit markers or just reflectors. The Shelby VIN plate is intact and in good shape and still attached to the fender apron though the drivers side apron has been replaced so this is laying loose.

The engine (short block) is not original and is a 66 428 A code and not the original 428CJ C code that came in the car. It has a complete running (as of 8 years ago) engine minus the smog. The Holley carb is correct but is a 1976 over the counter unit with all the Ford numbers but the date being correct. Intake is the correct C80OE-9428-C cast iron unit.

The transmission is original as I believe is the rear diff. It also for some odd reason has the 67 Shelby wheels on it and not the 68.

The original Lucas running lights are with the car.

This car will need a COMPLETE nut and bolt restoration with much of the sheet metal needing to be replaced. The interior is all there but not sure how much can be restored vs having to be replaced. The Shelby console is there but has a small dent in the vinyl from one of the interior panels laying across it and I am not sure that will come out.

The seller has given me a price (that he was offered many years ago) and I told him he should have taken that and run. I believe it is worth a little more than half of what he is asking. Any help based solely on my description would be much appreciated. I will not post the VIN number at this time as I do not want to lose the possibility of buying the car.
Thanks for any help and opinions.
Rick