Hi, glad I ran across this. I have an Ender 3 and AnyCubic Photon. I've printed pieces as small as signal heads for N scale, to pieces to construct my 4'x8' CNC machine. I've done a lot of design work in Fusion 360, some for modeling, some for real-world items. It's awesome to see an O scale repo being put together. I don't want to step on anyones toes, but I see two things missing, or clarifications that need to be made with these models.
The submissions in the catalog have the person's name with the picture, however there are 2 Carl's who have contributed. So, which Carl contributed the "Block and Dwarf Signals". Might be better to keep the member usernames there. The other thing that is missing is a readme, or a text blurb that should go in the actual repo with each model. Again, using the "Block and Dwarf Signals", there is no citing of what he used for the post. It would be useful to ask for such information since the model heavily depends on what piece was used there.
Other submissions such as the Bidirectional Signal by Alan, is a single STL. It probably should be broken up into separate components for printing, or a STEP file, rather than an STL should be provided so a user can perform more manipulation to split it apart themselves. It was also seem that parts of that model could only be printed using a resin printer, based on how the parts and orientations are, using the arm with signal head attached as an example.
I'd make sure as people submit models that they have to describe how it's printed (if it's not obvious), and what other components must be used if they aren't included in the STL packages themselves.
If you need any help, feel free to reach out, I do the 3d printing and design stuff in my spare time, but Linux admin on servers, and web design is my primary job function these days.