And the Mystery Object was . . .

The mystery object again.  Very carefully made.  Cunningly wrought.  As some of you guessed, a trap of some kind.  It's actually a rat trap.  It has a really strong mechanism - the dealer nearly took his fingers off when setting it to show us what it did! I should imagine any rat who fancied his chances grabbing the bait and doing a runner, was soon disabused of THAT notion - and pretty flat by then too!  Probably a West Country rat trap (they grows 'em big down there!) and gosh, VERY affective!