Charles,
Having heavily researched the Stuka, one of the biggest misconceptions on the design is the shape of the ailerons. This is because the 3-views that are out there, and I mean almost all of them, show the ailerons tapered. The actual full scale Stuka's ailerons were constant chord. THe funny thing here is that it is hard to find documentation that shows this, other than actual photos of the plane, which trump anything else in competition docs actually. So as far as competition goes, tapering the ailerons to match documentation would be in most modelers best interest, unless they can locate a 3-view otherwise. Out of all of the books I have on the subject (over 10), I have 1 3-view that is accurate. Plastic models can be notoriously out of scale, as will be freely admitted by the plastic modelers themselves. So they must be used carefully.
Not that this is an issue with your model, as you have enlarged your flaps for stunt flying, but I thought I would point out this little known fact about the Stuka. I am in the throws of building a Ziroli giant scale Stuka, and not sure when I will get back to it. But it has always been one of my favorite aircraft.
Rich