Tom,
I think where things went wrong is that you stated Elmers website, when it is in fact the John Tom website, and the engine you mention has nothing to do with Elmer Verburg.
If you go onto the Elmers part, you will see his #3 engine.
I also had a look at the plans for the one you talked about, and even though I am almost brain dead with regards to figuring some things out, I couldn't see anything basically wrong with the plans, just make the parts shown to VERY FINE tolerances, hammer it together with 6" nails and gorilla glue and it should run.
John