I might be crazy! Looking at a 64 chieftain? 21' twin 50 mercs, cabin style, resto project. Clean looking hull for age, rest is rough! How much is it worth?
The real value there would be the trailer and the twin merc if they have been well maintained. The hull itself, needing a new deck and transom is worth about 1k probably.
If the trailer is in great shape(not too likely based on the age of the vessel) and the merc 50s are running then the rig could be worth more. Even if the merc don't run parting them out along with the dual controls would get some cash on ebay.
I hope you get it, sounds like a nice resto project