Thanks for your response gentlemen.
AQ500:
Beautiful! That looks like a pretty hot twin, I'm wondering what the weight and wing area came out to be.

Mr. Mathews, I have plans for a PBY by one of your countrymen. I saw photo's in several magazines and contacted the builder.
The numbers in my post were based on the two .19 diesels, but I may make the nacelles large enough for the two ST-.34's, just in case.
I agree about the 800 sq inch wing. I'll get serious about the numbers now.
I have a Kadet Senior that I am modifying to resemble a cub, and I have always liked that kind of light construction, my original thought was a built up fuselage with a balsa sheet/plank skin. I'm pretty comfortable with that, I've never done much with glass on a model.
I do plan to use a lot of high strength and composite materials to reduce weight.
Haven't had much luck with Amonia and balsa however I've only used "grocery store" amonia. I might try to get some higher concentration from the local blueprint company.
As far as "cheating" on the airfoil is concerned. I have no problem with that. I don't even have a problem with flaps!
I'll take a look at the airfoils you mention thank you.
It's nice to have other modelers to bounce Ideas off of before you spend a lot of time and effort!