Thanks again! I had some technical issues I needed to work out and have been gone for a few days. I eventually got my system to find Windows again by creating a boot disk for the boot repair program. It was able to write me a new MBR. After all those issues, and the fact that I was still very new to Linux, I decided to reformat my Linux drive and install Mint again, but 19.3 instead of 20. I figured 19.3 would be more stable and more things would work. The jury's still out on that theory.
I haven't had a chance to dig into Lutris, yet. It's still a bit daunting with me knowing nothing about Linux. Also, since I haven't installed anything else, I couldn't even test it to see if it worked, then I've got (at least) 4 possible points of breakage (Lutris, Wine, Island Rum, CoH) and no idea how to troubleshoot.
Now that I'm running 19.3, do you recommend going back and trying your instructions again, first?