Hi Matt,  Lacking a clever response to your comments about the
liability of such a device, I'll just use all 10 of my fingers to type
the following.

I'd be willing to wager that there is missing a wooden clam-shell that
encloses the whole spring device.  It probably splits down the center
into left and right halves.  When installed, it would enclose the wooden
base, including the triangular part at the front.  Slots on each side
would allow the 'stirrups' to project through and move when the rider
leans forward and back.

The horse (or pig) would move primarily front and back, parallel with
the floor (no tipping).   But it would also move down a couple inches at
the extreme front and back.  Notice the strap spring under each horse.
At each extreme, the tip of the spring would touch the top of the box
and limit how far the horse would move.

Now I wonder how they would decorate the box.  Perhaps we could send
Robbie on a fact-finding trip to Hungary to find out!

Regards,
Craig Smith
Western New York

P.S.:  Here's an alternate view.  Perhaps those big springs aren't as
strong as they look.  If that's the case, the horse could move a lot
farther than I thought.  It might even go so far that the tip of the
strap spring would touch the top of that oval thing at the top of the
post sticking up out of the triangular block at the front and rear of
the base.  That would make for a very exciting ride.  Talk about an
accident waiting to happen!

 [ I performed in Hungary on two occasions and I'd love to return.
 [ Buy a plane ticket for me, Craig!  -- Robbie