Hi Dave
I took two pics this morning...
The first one shows the two different wing molds, taken straight out of the box. The flap chord is indeed ~5mm on both wings but the total wing chord is not identical. It is about ~4,1mm on the A319 and ~4,3mm on the A321 (measured with a ruler).
The trailing edge on the A321 wing is marked red so that it is easier to see on the next one..
And here's what it looks if you put the A319 wing exactly above the other - I think, the now visible red area more or less corresponds to the drawing in the Flight Magazine article..?
So, I further think, if I would cut down the A319 wings flaps on the trailing edge by 1,6mm to '0' (as mentioned), the wing chord will be too short.. (this only works by using the A320/321 wing)
The second option is scribing smaller flaps...the only problem seems to be that if you reduce the flap chord by scribing new lines, there'll be a spacing between the flaps and the air brakes that is not visible on the original. So, in my opinion, to avoid this spacing, we would have to fill in and re-engrave the air brakes completely new, too - a little bit further back..?!