I found a switch that can be modified to work as a push-pull, on-off
switch, of the right size and capacity for motor switching.  Unfortun-
ately it is not too simple.  It is a modern switch which I bought
surplus so hopefully a source can be tracked down.  It is marked Arrow
H&H and has a stamped number CHH24684.  I would guess that this is now
make by Cutler Hammer.  It is a heavy duty limit switch that turns off
when pushed.

Not thinking of much use for such a switch, I only bought 5 for 25 cents
each.  I should have bought the box full. The switch is 11/16 by 1-1/4 by
5/8 inch deep, with a 1/2 long 0.4 (?) inch mounting nipple, so it can
be adapted to fit almost anywhere.  The push-button is a heavy chunk of
brass that can be drilled and tapped to receive a threaded rod, or can
be drilled and soldered to.  It is riveted together but can be easily
drilled apart to modify the innards.  It is a snap-acting wiping switch
just like most modern toggle switches.  There is a spring-loaded push-
to-toggle lever mounted in the barrel.  By pushing out the pivot pin and
removing the spring it becomes a bi-stable push-pull switch.

It is a little strong to be operated by a leaky pneumatic or a lever
with stripped wood screws, but can be softened up a bit by shortening
the toggle spring.  Then the whole mess can be screwed back together
with #4 machine screws and Loctite.  The new switch can be a pull-on or
a pull-off, depending on the orientation of the cover when it is
replaced.  I checked all the catalogs I have and have not found anything
that would work as-is.

I would be hesitant to use anything from J.C Whitney without checking it
out thoroughly first.  I have bought things from them that one couldn't
think could be made badly, but were.  They also seem to buy seconds and
sell them with the name removed.  All the electrical items I have
purchased from them failed prematurely.  I keep their catalog for
reference but will not order from them.