Driver installation
Turns out that the touchscreen driver installation process was slightly more involved than simply telling Windows to use a certain INF file. There's also "Touchsetting.gt" and "GT912_1040.BIN" that needs to be copied into your windows\INF folder.
I also don't think installing the drivers via the Device Manager works as it should, so you have to use something like devcon.exe.
I've managed to bundle all the original files and script this process, in case anyone still needs these drivers. Tested it on a squeaky clean Windows 10 Anniversary Edition install and it works on my machineTM. Obviously you'll still need a OTG/Bluetooth mouse/keyboard to be able to log in and run this batch file (install.bat).
https://1drv.ms/u/s!Atqf9izYEbXKh6soSvO0OgHn6rM04w
I'm trying to get one of these tablets running with Windows 10. I did the upgrade not saving anything, so now the touchscreen doesn't work. Tried above but it's just showing "devcon.exe failed". Anyone who might be able to help with this?