Please help with your opinion on this 63 GT Vert

I’d tell him I would buy it right now for $4,100 as it was shown in the ad pics, and it needs to be running & driving.

This could be a really nice car but financially you’ll be upside down on it immediately no matter what price you pay.

Not in it for the car to keep, so being upside down isn't going to happen.
I have a rule where we don't pay more than 1/2 what something is worth unless we want it to keep.