I am lost in the Linux printer driver labyrinth!

If you have a ppd file for your printer, might be possible to use gutenprint.

This using Kubuntu 16.04 and Gimp 2.9.9 (from ppa) No entry for my Brother printer, so setup as:

screenshot: https://i.imgur.com/wfeyish.jpg

The only ‘issue’ I had was the ppd file permissions, had to change those to read/write for everyone, otherwise Gimp sends error messages.