You are qite right clipboard, fly this wonderfull errie until it does not fly anymore.
5Y-RAE ex ZS-OLX EX PH-RAE is s/n UE 18 is an aircraft that I spent many hrs mending.
True story:
the now defunct Aviation Assistance had a 1900 C with timex engines.They got permission from the Danish CAA to fly the a/c to altitude and 5,000 lbs of torque for one minute.The pilots reckoned that the a/c was rocking and rolling but the engines and the airframe stayed together.It says something for the a/c however I,m not too crazy about the tail feathers.
So , guys and girls if the torque fluctuates but the N2 stays normal ie 1700 rpm , in a perfect world , fly the a/c.
The other interesting thing that I experienced in Algeria was that on a very hot day the pilots reported that the prop could not reach 1700rpm.The m/m says that under those circumstances the prop will not achive 1700 rpm however the primary gorvernor can be adjusted to give you 1720 only, because as the oat gets colder and you guys set descent power the prop is going to over speed everytime, and that will put a lot of strain on the overspeed gorvernor.
The only engine failures ie -67D that I have heard of was the 2 1900,s from Rossair Europe , out of Hamburg with passengers.The cause was the failure of H.P. pumps on both a/c