Got the Rock-It Launcher schmetics and all 4 pieces of junk required to make it....firehoze nozzle, vacuum cleaner, conductor and leaf blower. Take it all to a workbench (like the schmetics notes say to do) and there is no option to create the Rock-It Launcher weapon.

Someone made a video showing the problem very clearly:
http://www.youtube.com/watch?v=Hn8rmCtle6Q

It was removed from the game (no idea why) but they apparently did not remove the schematics.

It's a bug, sorry.

The official Prima guide list the schmetics as an item in Nellis Air Force Base section. But oddly enough does not list the actual Rock-It Launcher in the weapons section of the guide.