Not a PT-19 or FW-189.
Herman has it with the lovely Stampe SV4, in this case the SV4C, a Belgian biplane very similar to, and often confused with, the DH Tiger Moth. The SV has ailerons on all wings, and a large rudder, and is a beaut to fly (although I had a tendancy to over-compensate with rudder!).
Here is a British registered example at Duxford.
Your shot Hermann.
That looks like a warning triangle on that frame, so a bit of a stab, as the rivet line doesn't really fit what I'm thinking. Harrier T2 (or whatever the current equivalent 2 seat traiing version is).