Thank youThere should be a hole in a cross member towards the rear of the cab. My Mimi has a cross member with a threaded hole where the trailing truck mounts. Take a look and see if this has been done on your Ruby. The pilot truck and trailing truck are exactly the same on my Mimi so this should be possible.
Thanks Charles,The pilot truck is all metal. It might be possible to use the screw holding the boiler to the cab floor. However, the trailing truck is moved back closer to the rear beam on the loco. The trailing truck will not be mounted at the correct angle and will be sloping to the rear of the loco. The cross member on my Mimi is screwed into place and could be removed. If yours is the same, a round rod between the frames, this is where the trailing is attached on my engine.
IMHO, the only safe way to do this is to drill and tap a hole for the trailing truck where you need it. You may have to add a new cross-member to get it in the right place. I certainly would not suggest using a boiler mounting screw.My Ruby has a small cross member but no hole drilled in it