Information is definitely out-dated, and you shouldn't really take it to heart.
The Golden Skin was a skin specifically for the M93R. It was added by, and to be used by only PlaceRebuilder in v0.4.2. This skin has since then been removed in v0.7.9 due to the M93R being converted into a mesh.
Supposedly, the M4A1 had a Golden Skin too. If so, then that skin was removed was in v0.5.8, along with the gun itself.
Anyone who bought it was permanently banned, as the only way you could buy it was through glitches.
If you have bought The Golden Skin and have been banned, please contact Jopede or Zilth on Discord or Roblox, and they will unban you.
- In PlaceRebuilder's inventory, the 'Brass' skin (for the Rambo Knife) was under the name of 'Golden' until Place renamed it.