I may disagree with others on this one........my opinion being it greatly depends on the condition !
If it's like a time capsule boat, kept dry, tight, clean and shiny therefore in " like new condition" then it should sell for quite a bit more. Reason being......new 20' at AC boat show at $ 64,000 to make an extreme comparison.
Granted, wood construction in V20, and if original fuel tank, plumbing, wiring etc means it's an old boat. If water has permeated transom or other parts of hull, bigger discount there too...
Motor.....same scenario.
So, I suggest you consider pricing your rig based on:
1. Book values - Kelly, etc to get a base line.
2. Add value for any newer equipment - electronics, etc.
3. Check comparable sales, to compare what other's have sold for in worst, roughly equal or better condition.
How to sell - market what's good about your boat, list with several GOOD pictures of your boat in shiny clean condition. Don't stretch the truth, but don't hesitate to list what's good if it is.
As for actual selling price, I'd be guessing without doing this research. Could go for $ 500 if rough.......could sell for $ 8,000 if museum condition.