that key is actually a transitional key from the old (and perhaps truly "vintage" (for hotel operations, anyway)) metal keys to the newer technology digital access control devices.

The "key" you offer is actually a more modern, digital device, than it is an older mechanical device. Older devices required insertion into a "pinned" cylinder lock, while the device you offer required insertion into an electronic, programmable recepticle. The key itself was programmable at the front desk, in a similar manner to encoding a modern day PVC card with a magnetic strip.

Please don't get me wrong. The key you offer is not all that common, but seeing how the Rio was opened in 1989, it's a stretch to call this modern, digital device "vintage".

Good luck in your offering.

Jim Follis