The 601XL I'm building is designed with a simple ON(mom)-off-On(mom)
flap switch. I was wondering if anyone makes a gizmo that would go into
the circuit that would allow a single momentary push position the flaps
into 10º then a second would move it to 20º and so on? Obviously the
same going the other way.

I could live with a gizmo that just ran applied the power to the flap
motor for X number of seconds either down or up for each push as long as
X is something I could set.