How rare is this and what's it worth?

Went thru the "interview" when I bought my 64 Rambler Ambassador. There was a lot of family history with the car and grandma did not want to let it go easily. The process was to ease her mind and I had help from family members. Still was a tough day when I picked up the car. The poor old girl was crying and she could not even watch as I loaded the car on the trailer. She was headed for the care home and passed away about 6 months later. Her granddaughter is my sister in law, (all by marriage), so I keep them updated about the car periodically. Still own and drive the car, likely always will. Seems to have worked out well.