Okay, it is not as exciting as the title but: I would like to find a copy of Ontario Provincial Air Service's Drawing 1501. That drawing is referenced in the FAA's TCSD for the DHC-2 under item 206 "Lumber and equipment installation" for carrying lumber as an external load. Since it is in the TCSD, as I read the rules the plane would not have to be operated under Restricted Category for external loads. I have called Onatario Dept of Natural resources aviation branch which is the successor or OPAS, and Kenmore both to no avail. Google and Bing come up with nothing.
a free donut to the person that helps me find the drawings.