A top-rate model and a much-welcomed addition to the Nn3 market.
I've reviewed the first and second test printings and am thoroughly pleased with the results.
The shell has plenty of room inside to add the necessary weight for electrical pick-up, but the cab also has plenty of space to add a crew on the footplate.
The design of the shell allows for a secure fit onto the Märklin chassis while still being easily removeable to perform maintenance on the mechanism.
I recommend first allowing the shell to soak for at least two hours (for best results allow to soak overnight) submerged in Heptane (rubber cement thinner, a common brand is "Bestine") to remove the usual wax support residue.
Then smooth out any trouble spots with at minimum-800 grit wet/dry emery paper (available in auto-parts stores such as Napa) then spray with a coat of primer before applying the desired livery and any extra detail-parts.
One detail which will have to be made by hand is the pair of handles that go in the center of the smokebox door. Small-diameter brass wire painted silver or grey will suffice.
This shell is pefect for any modeler who is interested in trying their hand at Nn3, or for any Nn3 modeler who is looking to add some variety to their locomotive roster.