Cement Saul is a fairly new YouTube channel that has been doing a bunch of interesting Gaslands-related videos. I especially like the video on Weathering with Coloured Pencils and Pigments. Pigments (pastel chalk dust, or similar) are familiar to me and I’ve used them in the past, but weathering with actual coloured pencils hadn’t occured to me and I’m going to have to try that out! It’s part of a series on painting, stencilling, detailing, and weathering cars that’s well done, approachable, and worth your time.
Light Industries is a Canadian outfit that do various decals including custom work; I always like to find Canadian sources for things when I can!
Misc Minis do various decals as well, including tiny decals suitable for 1/1200 vessels or aircraft. I contacted him back in January 2021 about getting a little sheet of his smallest decals, got it in just a few weeks for much less money than I was expecting, and will do a proper review of them sometime soon!