Hey...
i was in the same area a while ago. I had an old 1968 OS .35 and NEEDED to run it on the bench to figure it out and test it. I determined that it was just too old and too tired to run properly. I decided to get a new TT Pro and built a test bench like you did and just run a few tanks through it so i'd feel better on it's operation. I later put it in the plane and did some trials that way too. I think it is a good idea to do what you are doing... just make sure you get that prop on there.