I love how Intel stopped using numbers because they couldn't be trademarked and a competitor kept making their own 486. Intel named their next processor Pentium instead, and Cyrix just named theirs the 586.
I've also just mapped it to Ctrl+Alt or something as well. But ultimately for a daily driver I just got a Unicomp with the super key and use my old one with my retro rig now.
So yours is almost 40 years old, nice. It's amazing how far technology has moved in that time and here we are still using these ancient keyboards... they have seen some things we wouldn't believe.