Help me identify....

I picked this up over the weekend mainly just for the carb, but the little keyed box has me curious as hell. The guy thought it might be some type of governor? I have no idea. I figured it wouldn't take long for someone on the Hamb to figure it out. So what do you think?

 

What does the label say and what is inside?

 

no name just K 81 2 stamped in it. I do not have the key to open it.

 

It is a governor, with key to stop the delivery boy from cranking it up on his own.
Ford offered various governors itself, but this one is aftermarket.