When they made the Armored Vault 21 Jumpsuit, they just altered the Armored Vault 101 Jumpsuit mesh with a new texture and changed the item name. However, they didn't place it in the game world, nor did they place the activator (the suit that hangs on the wall in Craterside Supply) into the game world. I've altered that activator with a texture set to make it look like an Armored Vault 21 Jumpsuit and stuck it on the wall in Dr. Mitchell's bedroom.

http://www.newvegasnexus.com/downloads/file.php?id=36189

Also, another modder has made the jumpsuit purchasable from Vault 21 Gift Shop:
http://www.newvegasnexus.com/downloads/file.php?id=35502

...I just realized I misspelled "Armored" in the title...