Thank you for your help, Renee. Not sure if you were the one to respond on Facebook earlier, but between the help here and on FB, I was able to follow the youtube video produced by Bruce on uninstalling and reinstalling RM7 and it worked flawlessly. Now I have Mojave *and* RM7 and the restore of my data went smoothly as well.
The key thing here is to make sure that your RM “data” files are somewhere that you control. Do this by using Tools - Program Options - Folders. The best place to use is some subfolders under your Mac Documents folder, so ensuring that all your data is well clear and independent of RM for Mac.