Hey Onestone! I just saw your comment on the windshield washer switch over on my post, and I'd love you to forward the 3d printfiles/send me the links. I've got another idea I want to test out first, but if that doesn't work, your solution looks quite elegant. My switch is different than yours, though, since it's the combination wiper/washer switch, so it might need some tweaking. See photo below.
My Pontiac also has a bunch of the same options that yours does, if you want photographs of how something specific looks (like the parking brake light wiring) just let me know.