Wasn't the modern pen in the thrift shop? Which means it wasn't created by staff, it was a players item.
Edit: Just looked in the thrift shop thread to see whose pen it was, and it was Tricky's. Sooo I guess it was a staff's idea in that one.

Also the monkey skateboard trashpick, seeing how it has Monkey/Kota (player) on it, I'm assuming he made it