Do the rod in front of the drawers. I worked at a shop were some of the lowlife dung chuggers would pry open the drawers, so I drilled two holes thru the top lid of my Snap on chest and bolted a piece of 2"x 2"x1/4" angle iron that was 2" wide to it that I had drilled a 3/4" hole thru. Did the same on the bottom of the Matco roller cabinet. Then took a piece of Thomson hardened 3/4" dia. rod and carbide drilled a hole thru it about 1-3/4" of the end. I then welded a 1" nut onto one end of the rod, so that it would slide thru the hole in the top piece of angle iron and I could put a padlock thru it.
I then drilled a 3/4" dia hole into the floor and installed a anchor with a piece of chain welded to it that was long enough to come up thru the bottom drawer by 6 inches. I then fabbed a piece of 12 ga sheet metal that was 6" high into a rectangle that was 16" x 14". I then used a holesawed a 1-1/2" hole thru the bottom of the roller cabinet and the bottom drawer about 4" from the back.
With that I placed the sheet metal skirt over the anchor/chain and then rolled the rollercab over the skirt and using a magnetic pickup tool I pulled the chain up into the bottom drawer. That is why I drilled the hole near the back, so the bottom drawer could open 6" and place that hole of the center hole in the cab, this gave me access for my hands. Once I had the chain into the drawer I slide a piece of 3/8" rod that I bent into J shape thru a link of chain, thus locking the roller cabinet to the floor, and the skirt kept anyone from getting to the chain/anchor.
My Matco intermediate and SnapOn chest I riveted to each other and to the cabinet via their sheetmetal lips using stainless rivets - 3/16" diameter, about 15 on each. It was strong enough you could lift all three pieces via the handles of the chest if you could lift tham much weight.
So I didn't worry too much about someone getting into my box or taking it. I realize that a guy with a torch would make short work of the skirt/chain/rod/padlock, but we kept the torch head locked in a locked steel cabient on the tank cart. It ***** to have to do it, but at least you'll sleep a little better.Total cost of the materials was probably less than $50.
As to the owner of the other company, I would tell him what is missing and the value of it, give him one week to make good or else you'll call the police. With that they'll know you won't take it in the shorts and not do something about it. He has to know it was one of his guys, or else he would of been complaining that someone had broken in the place by know.
TheGrooveking