i thought NADA did have a classic car price guide
They do. But, I get a low retail range of $8,338 and an average retail of $18,975. By the description below from the NADA site I would consider it "average", but that's retail. (High retail $22,540) That's quite a range.
Low Retail Value
This vehicle would be in mechanically functional condition, needing only minor reconditioning. The exterior paint, trim, and interior would show normal wear, needing only minor reconditioning. May also be a deteriorated restoration or a very poor amateur restoration. Most usable "as-is".
Some of the vehicles in this publication could be considered "Daily Drivers" and are not valued as a classic vehicle. When determining a value for a daily driver, it is recommended that the subscriber use the low retail value.
Note: This value does not represent a "parts car".
Average Retail Value
This vehicle would be in good condition overall. It could be an older restoration or a well-maintained original vehicle. Completely operable. The exterior paint, trim, and mechanics are presentable and serviceable inside and out. A "20-footer".