RE: Royal-FW190A8
what I did with my P-47 was make a push rod out of 4-40 and mount my actuation piston just behind the cockpit floor under the air tank,I probably could have used the floor as a mounting surface,but it sits just behind the trailing edge of the wing of the so the weight of the metal piston is a bit forward and not directly on the tail.
on the FW I will do the same set up fortunitely the robart unit is plastic and quite light prbably too light for the Willhobby FW but strong enough for the Royal.