Ok, Solved it.
The key to the issue is I’m trying to migrate from 7.2 on a Windows install to 7.6 on a Linux install. What gave me that piece of the puzzle was KB Article 136, where there was incompatibility between the Win and Linux installs’ directory structure. It was just worse in my case because I couldn’t even import the backup.
So, my endgame scenario was to make a Win7 VM with 7.6 installed. The import from 7.2 went ok. Backed up the Win7 VM gateway and imported the resulting file into the Ubuntu VM. Perfect! Now I can go through and start tweaking my projects, so that when my project money finally comes through, It should be a much quieter transition. At least, that’s the plan… 