@Greg47
Yes… of course 200 USG is not a 50% overload. What is an overload to you ? An overload to me is any weight over the normal maximum operating weight.
I recall that Noonan told Collopy from the DCA, that when they would be leaving LAE they would be about two Tons overweight. Two Tons Imperial is 4480 lbs but in the U.S. in the 30's a "Ton" could mean 2000 lbs,,,,ie 4000lbs overweight in that case...
Therefore, to straighten out what you mean by a 50% overload:
What ZFW are you working on and what Max Normal Operating Weight are you working on for a Model 10E please ? I get the feeling we are talking at cross-purposes....
As you probably know, the Electra was never flown at the 16,500 lb weight on which LR487 is based. With a maximum original fuel capacity of 1200 USG being 7200 lbs, the Zero Fuel weight would be 9300 lbs which in AE's use, it never was... and I am not saying that is the ZFW you are using. So what is your ZFW and Max normal operating weight ?