Got the problem solved- - - - -do it yourself and don't bother the professionals. After a few scattered engines because of a simple mistake the guy who has been building them for a lifetime would have spotted and corrected in the first place, it might begin to sink in that it takes more than a basic understanding of engine principles to be a successful builder.
The pro won't mind letting you get in on the expensive learning curve- - - -it's something he did years ago, and he's going to be busy working for someone who appreciates his expertise, and is willing to pay for it.
Jerry