Actually, it is the same method Dave, just make sure you do the right material. It's the one with the "prop.bmp" texture. Should be the last one in the list.
You'll need to do both the interior & exterior mdls.
Looking at the flap settings in the FSX Maule i can only see 0%/25/50/75/100% on the flap lever but on 0% settings looking at the flaps with outside view they are facing up slightly and at 25% they are level with the wings.
OK Roger, that seems to be the same result except that I think you have an extra setting (100%) and my -7% corresponds with your 0% and your 25% is the same as my 0% then I have just the 50 and 75.