+Most of my banner towing has been with a Sig Kadet. I also used a smaller plane in the 60's. On my Kadet I have a bomb bay door on bottom of plane, and carry the banner aloft Also drop parachutes and can drop canddy or what ever. When I was in Navy I was assinged to Fighter Squdreon VF 111. When we went to El Centro. Ca for gunnnery practice. The Jets pulled the target Banners off the runway , with the tow line stretched out along runway. It has been since April 1954 since I was with VF 111 and I don't remember how the banner was attached to the jets but it was to bottom of the jet. They could drop it if they had problems . When they were ready to drop the banner the jet would drop it along runway.
I am an Airframe and Engine Mechanic and had in the past attached a tow rig on Super Cubs and Stinson L5 to tow Gliders and banners. The FAA approved paper work was to attach the tow hook up to the airframe at the tail wheel. I have never towed a Model glider up but have seen pictures and the tow hook up was on top of fusalage . Thes are just my Ideas . BOB MOORE