Marx Animal Train engine and coach, blow molded, hard to find!

Here is a real oddity amongst Marx toy trains.  Sometime in the sixties (I think), Marx made a soft plastic, squeezable engine and two coaches.  The engine and one coach are in this lot.  The engine is a black plastic BATTERY POWERED engine, marked with the number 737 under the cab window, and with MARX ELECTRIC lettering on the tender.  The coach that is here is the “Duck Car” in red plastic.  I believe that the other car, which is missing, is the Cow Car or Cattle Car.  Quite a rare set, and one many people haven’t ever even seen.  Now the bad part.  The engine is missing its wheels, and the cover to the battery compartment is also missing.  Couldn’t get it to do anything either.  The Duck car should have a piece that fits in the bottom so that when you squeeze it, you get a quacking noise.  That is missing.  I’ve posted closeup pictures to show the missing noisemaker on the duck car, and the missing stuff on the engine.  Still, it’s such a rare set that I’d bet someone out there can put these two pieces to use!  Photos from all sides, so you get a good idea of what you’re bidding on.  Priced to sell, with only actual shipping costs charged, and I give you a couple of shipping options, so that you can pick the method that works best for you.