Hey Stork:
I have a pair of clone of Zorro systems on the old F12 BIOS, one with a 6850 and the other with HD3000 graphics that I upgraded last week from Mavericks to 10.12.4 using your Son of Zorro guide, using Clover, and both went perfectly, so a huge THANKS!
...I also got a 1050Ti card to upgrade the HD3000 system but can't find the config.plist to modify and the great majority of info on Clover is for UEFI systems. Any recommendations?
You should be able to find the config.plist file by:

Open the Terminal and run the following:

Note the Sierra drive's EFI partition's "diskXs1" designation - could be something like "disk1s1";

Run EFI Mounter v3 to mount the UniBeast USB drive's EFI partition;

The config.plist file is in /EFI/EFI/Clover/ folder.
However, for making the mod to the config.plist file for the Nvidia drivers, you can use the latest MultiBeast v9.1.0+ to
just select:
Customize > NVIDIA Web Drivers Boot Flag
Additionally, when you install the GTX 1050 Ti, you'll have to make sure the Inject ATI and NVIDA are false.
Speaking of MultiBeast, did you use the latest version of MultiBeast (v9.1.0) when you updated to Sierra 10.12.4? If not, you might want to want your whole configuration with the latest MultiBeast to update the drivers & kexts. Backup your system
first, though.