I wanted to add more levels to Axels design so I have added bridge that can be put above existing pieces.
All parts in picture are 200% scale.
If you want to snap to original should be ok, but in picture I have scaled by 200%.
All parts printed with PLA on its side.
Brim was not needed, but depends on your printer.
The author remixed this model.
I have used the top of stairs and removed the stairs, made long bridge and mirrored the snap on the other side.