Gosh, makes me wonder what mine is worth. Not!!! Other than the supercharger this is a clean nice GT/CS with a great color combination. Looks like a very nice car, but $53k is certainly a stretch. My GNS has a myriad of modifications to handle the HP a supercharger will put out. 9 inch with 31 spline, hardened automatic, subframe connectors, export brace, and not to mention a purpose built engine to handle the supercharger in the first place. The extra stress of a supercharger will blow the connecting rods right out of stock 5/16 inch rod bolted 289. Not to mention head gasket problems and such. I did this basic build back in the 1970's and learned very quickly!! I guess if you never drive it hard it would be ok.
You could nearly buy two Neil restorations for this price. If someone is interested, I would take a hard look at the rear end housing. Someone has "grafted" in a set of coil springs on top of the housing as an assist to the leaf springs. Pictures are not close or clear enough to see what was done. I suppose if done correctly it may one way of curing rear end sag. I have never seen anyone try it before.
Rob