I don't know what it is, but it's good looking plane. 7 lbs though on a 46" span is quite heavy. I've got a SuperAeromaster bipe I built from a Great Planes kit and it weighs in at 9 lbs and it is 54" span. It called for a 91 or 1.20 four stroke in it. I couldn't figure a way to shoe horn in the 1.20, so I settled for a 91 magnum four stroke. I have yet to fly it though.

Check the engine mount if it is still in and make a guess on engine from it. I doubt that a 46" span would be happy with a .40. Maybe a 70 four stroke though. A good look at the interior construction will give you a clue. From the looks of the construction, the wire landing gear setup, I'm guessing this plane is probably 70's or 80's vintage. Just a guess though.

Don