Thanks; neat project and a just generally interesting blog.
I haven't worked with 3D printed parts yet. Might first try my hand at some of the new ships for the old Starfire board/miniatures game before diving in to railroad models in that methodology.
later, Forrest Today's scientists have substituted mathematics for experiments, and they wander off through equation after equation, and eventually build a structure which has no relation to reality. -- Nikola Tesla, July, 1934