This key fits with the antique lock I recently uploaded.(http://www.thingiverse.com/thing:2205692)
There is a nice looking version with a full rounded shaft and a flattened version to easily print.
If you were wondering the specifications for the key:
Tip = 6mm diameter and 6 mm from teeth
Teeth= 15mm high and 5 mm wide
Gap = 5mm (between teeth)
The radius of the key 16.9mm and any larger probably won't fit in the lock