Thanks for all the great replies.
The engine I am trying to start came with my project and had a "story" that it was a crate engine...so I figured that if I was lucky, it MIGHT have been rebuilt. The oil looks brand new and the area behind the pushrod cover is very clean, so it is not impossible that the engine will turn out to be functional...I am hopeful that turns out to be the case.
The idea that I should put a muffler on whatever exhaust system I come up with for the test makes sense. I see that the flexible steel exhaust tubing is readily available at the FLAPS. The next thing I should do then, is figure out what I should do for a muffler that I could use on the permanent exhaust system. Quiet would be an important quality for both testing and final installation. Any suggestions as to what to use or what to avoid for a muffler?