I posted this on Reddit but thought I'd post it here as well - how to program this keyboard:
1. Follow this:
https://docs.qmk.fm/#/newbs_getting_started I initially skipped it since I had the QMK Toolbox already but no, you have to follow this all the way through until you have an environment that you can run the "make" commands in. I was skeptical about actually installing MSYS2 on Windows but it worked really well. Don't be intimidated by the CLI work. :-)
2. Grab worldspawns's firmwares:
https://github.com/worldspawn00/Firmwares I think the QMK newb guide talks about using git so use that same process. This is all their firwmares so what I did was download this to a temporary place and copy over gothic70 to qmk_firmware/keyboards/ folder, so you should have qmk_firmware/keyboards/gothic70 when done.
3. It's a good idea to create your own keymap folder so you can switch back to default if you want. So create a new path at qmk_firmware/keyboards/gothic70/keymaps/<new folder> then copy over the two files from default folder: keymap.c and rules.mk. Edit keymap.c if you want to change your keymap.
4. If you want to change the number of LEDs to light up, edit qmk_firmware/keyboards/gothic70/config.h line 33 (#define RGBLED_NUM 7) - change the 7 to the number of LEDs you're using. I updated mine to 38 :-)
5. When you've got it all ready, while in the qmk_firmware folder, you'll run: make gothic70:foldername - foldername being whatever you called the folder in step 2. And of course, if you wanted to build the default firmware, you'd run make gothic70:default.
6. So you can flash from the CLI but I chose to use QMK Toolbox since I already had that setup - I liked the visual of the keyboard being attached. You'll need to find your hex file that is generated from the previous step. If you are using MSYS2, run "start ." to open a file explorer window at that location. Open this file in QMK Toolbox. Hit the button on the bottom of the keyboard and wait for the line in yellow to say the controller has connected (I forget the name now, typing this from memory). Click Flash. Enjoy.