i took a proto taco wagon like that to over 400 dollars at an auction last spring. i still kick myself but i know the other guy would not quit. his shop had burned down and he had insurance money to burn. the one i was looking at had a 1 1/4 thick aluminum shelf attached to it with a vise monted on the shelf and aluminum on the top of the chest. it was well made and looked good on there.
Did everyone make a "taco wagon"? I had never seen one before joining this site but now I have seen Matco, Snap-On and from what SK Farmer says, there is a Proto taco wagon too. They look really cool and I would surely try to buy one if I found it locally.
That is an MB1400, I call it the Hot Dog wagon, some call it the Taco wagon. Great box IMO. The drawers are deeper than 12", they are more like 16". I have one sitting in my garage.