The low power comes mainly from the use of a standard glow plug, the threads of the plug becomes a part of the combustion chamber. With a proper glow plug like a turbo (or Nelson) one the power is fine on glow. As a comparison all cox and Norvel all have a button plug, and loose a lot of power if one would put and adapter for a regular plug, like the ones sold by Meccoa for instance.

So the low power of the stock engine is not a good measure of the potential. It can quite easily be put on pair with the Norvel and it should work very well as a diesel.

The only thing do I have an issue with is the sloppy crank, there is a clear radial play straight out of the box...

I think it is an excellent project, please keep us updated on the progress and good luck!