Thanks for sharing your find. Looks like the car is sort of in between something that you could clean up and a car that needs a restoration. You will need to do more investigation into many things and do some cleaning to determine what the best path to choose IMHO. Maybe the new owner is here already as a member or may be in the future.
In an effort to promote discussion and understanding (not to pick apart a car just for that reason) I offer the following observations
A few things I found interesting was that I haven't seen the sound deadener on a fall 64 Dearborn car applied to the quarter panels in a pattern like that before maybe a fill in worker (short time in that spot on the line) or someone new.
Top edge of the quarter trim carpet section has the sewn top and outer edge something we've seen on some fastbacks from that period Can't make out if the car has any carpet screws
Looking at the bottom of the car it appears that the car may have had an earlier collision at the passenger A pillar so that fender may have been replaced.
Though pictures aren't really clear it appears that the brake and fuel line clips may be attached with screws rather than the expanding retaining clips at Dearborn during this time period. Which is interesting since San Jose was doing a similar things for a short period and filling the existing holes with dum dum
But all subjects for other threads
Again thanks for posting and sharing
The business did a nice job of posting allot more pictures than we see in allot of ads There is a reported 5,000 mile 73 that they sold so grabbed those pictures also to add to the pictures I already had of that car