how deep are your pockets?
that being said i found my 21 in a dirt field sitting on a load of tires bow down. anything is possible. but it takes time and money. based on the pix that boat is a complete gut and throw away. things like steering, throttle, gas lines, wiring, etc are all probably old cracked and rusty... and most importantly NOT SAFE! you'll have to start over from scratch. the fact that its been sitting outside you need to worry about structural things like the stringers and floor. they're probably rotten from standing water and will need to be replaced. trailer looks like it needs to be stripped and redone, tires, bearings, etc.
i didnt care when i started my project because i knew that i was going to replace everything with new. it just depends on what you want to spend.
im not sure how many hulls are laying around in your neck of the woods but around here a 21 cruiser can be found pretty easily in great shape for next to nothing.
me personally unless you had some emotional tie to this boat, i would walk.