I bought a Carl Goldberg tailwheel bracket from the hobby shop.

I cut a piece if 1/4" ply to fit the last couple inches of the fuselage. I then tapered the plywood to the size of the tail wheel bracket. I removed the covering from the rear of the fuselage where this bracket was going to mount. Covered the outside of the bracket with sticky monocoat trim the color of the fuselage. Epoxyed the plywood in place. Screwed the bracket to the plywood adaptor.

My tailwheel bracket was the Carl Goldberg with the spring interface to the rudder. This was attached.

The engine you have would run better upright or on its side. It will have plenty of power for the plane.

Enjoy,

jim