Took a few month as I had a lot of other things to do.
I´ve shelved the idea with the small sleeper as I don´t have enough info to get a drawing ready that would satisfy me.
What happens if you take a few small endmills, wait for 4 hours and let them travel for a few hundret meters?
It is straight from the machine table and hasn´t seen any sandpaper.
The four rectangular shaped areas are only 1mm high but feature a 30 degree chamfer and a 0.5 radius to make it look right
Hope I can fit it on to the cab in the next few days