Hello. How do you determine the amount of aileron that is safe to convert to flap? I am concerned with losing too much aileron surface. (P51D)

Should a person try to aproximate the scale amount?

Being a newbie, I must ask for the definition of a "monokote" hinge. Is there a thread somewhere where I can get educated on all of the hinge types, pluses, and minuses? Thanks Guys....Dave