Paul.
I understand your frustration about the measurements of the awning window you received, First, let me address the screen issue. All our screens are on back order mostly due to short staffing at our screen vendors, also delays with materials needed to manufacturing the screens, please be assured your screen will be shipped to the store as soon as it is received by us from the vendor. On to the measurements of the window. Typically the stores use the Rough Opening for measurements for ordering the windows. Their design systems are programmed to remove 3/4 of an inch off the width and the height of the measurements to aquire the frame size. This all depends on the accuracy of the contractors doing the measuring,. we do allow at least 1/8" tolerance for our product when manufactured.
sincerely
Jeld-Wen Customer Service Team