Would you care to evaluate your car's condition in order to set a fair price range?
Start with biggest factor, the car's condition. It appears yours is somewhere in the Condition #2-#3 range.
Hagerty's valuation tool currently says an '81 5-speed is currently valued at:
Condition #2 (Excellent): $51,200
Condition #3 (Good): $36,700
These numbers are both up by about 20% in the past 3 years.
Their #2 and #3 condition classifications follow - feel free to chuckle about the 'paint job' factor although that could apply to the fascias and wheels. There are D-specific factors, particularly the frame's condition, of course.
#2 vehicles could win a local or regional show. They can be former #1 vehicles that have been driven or have aged. Seasoned observers will have to look closely for flaws, but will be able to find some not seen by the general public. The paint, chrome, glass and finishes will all appear as excellent. No excessive smoke will be seen on startup, no unusual noises will emanate from the engine. The vehicle will drive as a new vehicle of its era would. The one word description for #2 vehicles is "excellent."
#3 vehicles could possess some, but not all of the issues of a #4 vehicle, but they will be balanced by other factors such as a fresh paint job or a new, correct interior where applicable. #3 vehicles drive and run well, but might have some incorrect parts. These vehicles are not used for daily transportation but are ready for a long tour without excuses, and the casual passerby will not find any visual flaws. "Good" is the one word description of a #3 vehicle.