The Pt-40 has a wing span of 60 inches and a hatch just behind the engine bay. I think it is an older Sig Kadet or Kadet MK II. You might go to the Tower Hobbies web site and look at the current crop of trainers. wwwtowerhobbies.com . All ot the above were good flyers but the original Kadet was a three channel and many were converted to ailerons. You could buy the aileron upgrade parts from Sig. The windshield looks like a Kadet which was carved and rounded.