To export the project in the .X or 3dl format?
There is an old .x exporter here. It was made when SketchUp 6 was current but hasn’t been updated so who knows if it still works.
What is a .3dl file?
Perhaps related to this (Russian?) product:
Or some ppl think Kodak started it, and it is an old undocumented format (similar to STL)
The first answer in this thread, posts what he thinks the format is:
… another reply gives this:
- Link for User Guide pdf file here: