Martin-Baker 3 pictures from Sir James Martin's Biography.
The MB.2 and MB.3 were both awful planes with totally inadequate stability and control. The MB.5 was similar until after 2 years of modifications. The test reports and reviews are from 1946 when it was flying well.
Here is a quote from the early trials in 1944;
"Greensted[test pilot] however remembered very clearly his first flight in the MB5, and he recalled ; "Right from the very beginning I suppose you could say that it was a badly designed aircraft because it didn't work in the sense that it was directionally unstable. It was an absolute swine to fly because it wouldn't keep itself straight."..."I still don't understand why the thing wasn't right when I first flew it. After all, the theory of design of aircraft at that stage was pretty advanced and I don't understand how he could make a mistake about the directional stability..."
Martin didn't design aircraft very well because he had no training in the field. In modifications like the 12-gun nose, flat feed for the 20mm cannon and ejector seats, he was excellent, but not for aircraft.