As far as I know, nobody makes
jump traps anymore, and very few
people use them (that I'm aware of)
Instead of leaf springs with eyes on
the ends of the trap, they use a
leaf attached to one end of the frame
and it goes across to the other end
inside and torques upwards to
shut the jaws. More compact than
a double long spring trap, kind of
an ancestor of a modern coil spring
trap.
Some years ago I bought a box of
old traps from a man that was cleaning
out his father's outdoor goods
from years ago, and there was a
few of these Blake & Lamb #1 jump
traps in the box. Most were usable
as is, but one is missing the pan
and arm.