Just some additional new images which showed up during this search. Fowler flap detail (not flaps, for there is only one!):-
Fully closed there's always a small slit for radiator outlet. This would be the setting for flying at speed:-
Flap in takeoff position (or when running hot). With the lever in this position the inner (hydraulic) root slats are also fully opened (and stay like that down to full flap down setting):-
I think I posted this one before, fully extended, but good for comparison:-
It's quite a bit of 'extra' wing. Goes right out to the dihedral. I tried to calculate the surface area but realistically I need a model to do that. I think the single massive Fowler flap with tilting nacelles one of the coolest features. Just repeating the earlier info from the official pilot's manual:
The maximum permissible speeds for various flap positions are as follows:-
(a) Flaps depressed about 10⁰, to give maximum cooling position of radiator shutters - 300 m.p.h. A.S.I.
(b) Flap depressed half-way - 200 m.p.h. A.S.I.
(c) Flap fully down for landing - 160 m.p.h. A.S.I.
I'm afraid I don't know how to calculate the corner speed, but getting half flap down already at 200 m.p.h. and then progressively more as you slowed would be very useful in an AH fight. The kind I always seem to end up in anyway
Additional to the root slats there were also automatic outer slats just like the 109. Bit of a cacky photo (sorry for that) but here you can make out the outer (automatic) slats flopped out. They are also pretty long!:-
The high-lift devices anticipated later commercial airliners I think it's fair to say.