Good day,
Thank you all very much for bothering to answer. I don't understand OP. Could you please explain that one to me Mesae. Is the OP me? On rereading your reply I guess it is

By "low wing" I meant that the model has the wing underneath it. Like a PT19.
The section of the wing is the same curve below as on top. That is eliptical isn't it?

The stabiliser is curved on top with a flat bottom. (Would that be Clarke Y, tailplane?)

The model was very docile to fly. It slowed down beautifully to land. However I have not had sufficient flights to test properly. When I get some more time on the engine it will be better to tell.
The up elevator trim in the longer term may not even be an issue but I would like to have enough knowledge to be able to test to see what the likely problem is and then make some changes and see if performance improves or otherwise, and also pick up some useful knowledge of what can happen.
I thank you for your advice.
Cheers
CdeJ