I would spend some of the money you saved on the deal and get it hauled home for some engine work (if it were me I would see if I could get a whole fresh engine and drop it in and not bother with twiddling with the dodgy one that's in there). You'll spend a little money, but your confidence in the truck will be high once it's all done right.
Of course, that's just what I would do.
Other than the engine, it looks like a solid truck. I would plan on changing all fluids, doing a full PM on everything and probably getting some new(er) tires if they are weather checked.
You saved some money up front (which is good), now you can invest a bit more and make it a super-solid runner that you can drive down the road with confidence and safety.
