@theluthier my hubs are (relatively) fine:

The inner ones are made by @duerer and the fit his rear axle, which is a bit smaller than my front axle.
There is a discrepancy that has to be resolved!
Is my axle too wide?
Is the rear axle too small?
Are both axles correct and are the rear wheels closer together than the front wheels?
None of the above?
I will look into why I put my wheels there, but I will not make a decision on what has to be changed, on my own;)