RE: LT-40, All-Up-Weight ???
I still have a battered old LT40 that I converted to a tail dragger. I don't know the weight at the moment but the plane is such a floater I doubt the extra weight will be much of a problem. You might want to make your first few landings with a little extra speed to be on the safe side.
You could add flaperons by adding another wing servo. The LT's setup makes this quite easy to accomplish.
I'll try to get a weight for you in a few hours.