N Gauge Rail Tractor and Truck (Motorised)

A humorous little engine (is this the smallest in N?), this model is a working model of a freelance rail-mounted tractor.  Often home-made, these unusual little units were common world-wide, particularly in industry for shunting and other light duties.  Also included is a motorised open truck (also available separately) designed to fit directly onto a motor chassis enabling slow-speed running.  

Necessary to Complete:
Graham Farish wagon wheels (with pins sawn off)
Loco coupling
Weight
Kato 11-109 Powered Chassis Pocket Line Loco
Buffers
Coal, sand, or any load to mask the motor cover