I am happy to report that my new Armin Devries VT-1D 1cc 4-stroke diesel is a winner.
After some running-in, I drove over to show chevy43, RocketRob, and Scallywag my new toy.
This engine is so different from my other diesels and my glow 4 strokes, I am still learning how to start it without taking half an hour!
It runs so well once started that I think the problem is just me. []

If I recall correctly, the rpm were as follows: (using Clutton Olde English fuel)

on an MAS 7x3 prop: 9000 high, 3400 idle (which sounds much lower, being a 4 stroke)

on an MAS 8x3 prop: 8300 high, 2900 idle (or there abouts)

I will be flying this engine before too long, and will post photos when it happens. Meanwhile, here are a few shots of the engine.