The engine on the plane is a Tower Hobbies engine, at least the carb is. It has the little Tower logo like on the tail. *Looks* like it says Tower Hobbies on the side of the engine but can't really tell in the picture. Doesn't matter, if it'll fire up, fly it like you stole it.

Looks like the OS engine in the middle of the three is an SF. Some folks say the SF line was the finest that OS ever produced, but I don't know.
By the scraping on the head of the engine in the plane, looks like it's gone in head first before and the LG looks like Toysrme type landings because they're kinda splayed out. No offense Toysrme, I do the same thing. LOL Looks like you got a awesome deal though. You'll have a lot of fun with it and there's enough stuff to fiddle with for a while. Just in case you *can't* get anything started, don't get discouraged. Ask advice here and keep fiddling with them or take it to your local field and you'll get everything going sooner or later.
From what I understand about the K&B's, they are more of a torque engine and like swinging bigger props at lower RPM's. I would leave the Tower engine on the plane if I could get it to run, then the O.S., the Evo and lastly the K&B. Good luck with it and let us know how you make out!
Pat
P.S. If you've never started a fuel engine before I would definitely ask someone local for help. Fuel engines are no more dangerous than electric motors, but they *are* more difficult to hold the plane, crank the motor with a starter, get the glow plug off and get it tuned, dexterity-wise if you know what I mean. If you're not careful and paying attention you can make a mess of yourself in a hurry.