I for one, can really appreciate the amount of time it must have taken to accomplish the engine build.
Back in the 90's, I built an Echo based 32cc twin. It is nothing fancy. The fact that I built it, tested it, and it still runs to this very day still amazes me. Not knowing how to do any of it, just basic engine knowledge and lathe and small hand made milling machine, it was a real challenge for me. Now, at age 63, I would never attempt it again, but have the highest admiration for anyone who does. I think by now, I have forgotten most of what I thought I knew back then.
Kudos to the craftsmen of the modern world!

John