ORIGINAL: uhu
...electric Me109G 48" WS that had very bad longitudinal stability, ...
Radios don't have interferences, pilot's fingers do have!
I know someone who flew real Me109. He said it was a terrible airplane - the tail is too small, especially the rudder. So a scale model of it will just be worse, since Re are lower. Build the next one light, and increase the tail volume a bit (by increasing the span) if you can get away with it.