Can this engine be saved?
 

Okay so I am still in the process of my rebuild and all of the following pictures are after I have done my best to clean the engine with denatured alcohol on the inside and simple green + denatured alcohol on the outside. Is this engine worth spending about $15 bucks to get new screws for it and thermo insulator or should I just buy a new engine?

Here are the pictures I took of all the areas I thought were relevant.

Engine Pictures

Depends on the Crank pin, how worn it is, how much slop the rod has while on the crank pin.
Also how much pinch the sleeve has at TDC.
Replace the front engine bearing as well.

Have you run this engine? you showed us the exhaust port side of the sleeve, it can get discolored like that. for 15 bucks I'd try it out. do the bearings feel gritty? and does the front one leak?

If not use the same bearings, because once you start replacing bearings when other parts are questionable. then it's not worth it. the corrosion on the crank is typical of an engine that has sat a while, like a winter without proper maintainance or storage. But if you clean it well with break clean and use alot of after run oil before you refire it up. hell, even a 15 dollar pinch might help. 30 bucks to revive a motor isn't bad.