Mike,

I pulled these throws from my old yellow aircraft manual.

Ailerons 3/8" UP and Down
Elevator 3/4" up and Down (Maximum)
Rudder 1" Left and Right

The only word of warning that I can give you is keep the speed up in the turns. Just about every A-4 that I have seen bite the dust was due to either slow in the turns, where it just feel out of the sky, or due to the engine dying, which again lead to a slow turn!

Good luck!
Greg