I am definitely interested, and I am very thankful for your time
OK, well this was quite an adventure but I think now I have the tools, VESA specs and math down to the point where I can manufacture monitor drivers. I can't guarantee that this will work since you don't actually
have an EDID to override but it should work (in theory). One thing you have that I need is your monitor's .ICM file. You need to put that in the same directory to which you unzip the attached .INF file. Also, I have no capacity to create signed driver catalog files at this point so you will be warned that this driver is not digitally signed. I don't really think we need to get Microsoft involved in this, do you?
So, without further ado, download this
View attachment 10375, unzip it to a working directory, copy the .ICM file from your original monitor .INF package to that working directory, start device manager and update your monitor driver manually. It will never automatically choose an unsigned driver so you'll have to use the "have disk" method to directly select the new .INF file. Once it's installed, log off and back on again and try your new resolution. If it fails try rebooting -- whether that's required appears to be up to the video card and driver.
Let me know what happens please as I put about 20 hours of work into this!