The term "cotton" meant thee are special features designed for use in the Cotton industry primarily in California, Arizona & Texas - one large costumer at that time was Cal-Cot Industries. A-C had a full time service staff to keep units running as this was a 24/7 operation during the cotton harvest season. From what I recall - the Cotton Units had other features like, LPS Safety features, high speed differntional -about 2 mph higher than standard, fly **** in the transmisson disc to get a positive lock up (when they were moving bales the brake pedal was seldom used - just trans reversals, a flat angle inching pedal with a strondear return spring to keep the operators from activating teh inching mode all the time - the spring gave them cramps if they did, the radiator wider spacing bewteen fins & in-line vertical tubes - so the lint wouldn't build up so quickly & could be easier blown out, there were two belts but only one was driving, the second belt was secured to make fan belt replacement quicker) on that model the hyd. pump was crankshaft driven, normally you would have to loose the pump mounty bolts & slide the pump back to instal a new belt. This two belt system was a time saver or course after the second belt broke, you would have to loosen the hyd pump & install two more belts. This belt only drove the water pump. There were probably other things but at this point in life I can't recall
In late 60's i wrote tech manuals (service, parts, operators) for A-C, in 1970 I started working in marketing & wrote sales literature for them - event the "Cotton Special".