Bachmann 2-6-0 "Big Hauler"

Bachmann has a very famous loco, called the "Big Hauler"

The first generation was battery powered, and had a small motor, plastic wheels. It had a multigear gearbox.

The second generation used the same gearbox, but had a better motor, and ran from track power.

The third generation was also called the "Plus" model. It has a better motor (but a weak motor mount), better gears inside (idler and axle spur gears). The motor mount would let the motor to move away from the cluster gear and strip it.

I need to detail the 4th and 5th generations, which had improved gearboxes

***need*** pictures

Note--the controllers came in two frequencies--27mHz and 49mHz. I don't remember if there was anything on the transmitter that differentiated them. The locos numbered #7 were 27mHz, #9 were 49mHz.