My way of installing it on my linux machine, for anyone interested, was as follows:
So, “game.gog” and “game.ins” are just renamed .bin and .cue CD image files. As long as you can extract or install those (really you just need “game.gog”) you can install the game in the emulator of your choice.
If you want or need it in .iso format, you can use a tool like “iat” to convert it.
I just installed the game from the windows installer using wine to get at these files, but there might be a more elegant way to do it.
I then mounted the CD image in 86Box, and installed it from there.
(BTW, I highly recommend 86Box or PCem to anyone wanting the most authentic possible DOS experience without a real vintage machine)
You can do something similar with many games on gog. Sometimes the files have different names, or are hidden in a different folder.