Today, after some conversation with the folks at 23B about various CAD programs, I tried to import the Solidworks assembly file into the Cloud-based semi-free CAD software "OnShape". It didn't work, even after I massaged it by making a new copy with all of the parts included as "virtual" (which saves them inside the assembly). It seemed to have trouble with sub assemblies and also with some parts that had been virtual in the original file but now no longer imported.
Solidworks "Pack-and-go" facility wasn't used because it had some sort of DLL missing and didn't work.

So, it looks like I won't be moving this project to the cloud any time soon...