You are right, Per, this shunter is pretty ugly, but not so ugly that she has to be hidden underground!
I chose her
only for the engine and the transmission; and most of the pictures I gathered show the loco without the bonnet, fortunately !

Roger, with all that I learned by following all your experiments, testing a fuel injection system was my intention at the beginning of the project, this engine dates from right before the diesel and was a good model to have a go...
But I had to leave this project this summer, and since I have lost its ambition and direction, and now, I'm trying simply to finish this small engine to the simplest and wishes that my model run like this stationary version of this 1905 Deutz engine.