RE: Engine name
RCGuy:
Jim's posted engine picture (from the MECoA web site) looks very much the same as yours. As Jan and I both said, HB never listed an engine larger than 0.61 cid.
If you are willing, and have the instruments, you could pop the head and measure the bore and stroke. That would settle the size question, leaving only the maker in question. The HB 61 is 0.9448" bore and 0.866" stroke.
Some other dimensions: Height overall (not including glow plug) is 99.0 mm (3.8976"), length overall is 89.5 mm, or 3.5236 inches. The outside diameter of the head is not listed.
Bill.