I think that the Piasecki HUP by Cascadia is too small.
Rotor diameter is 35 ft or 70 pixels hull is 56 ft 11in or 113 pixels, while the whole drawing is 77 pixels long.
Are you sure it's not 56 ft overall length? Using the rotor diameter as reference the hull seems to be some 25 ft.
Because with a heigth of 12 ft 6 in (3.81 m), 56 ft 11 in (17.35) seems very long just for the hull.
edit:
http://www.boeing.com/boeing/history/boeing/hup.page
This links says fusalege length 32 ft or 64 pixels. Indeed longer than my drawing, so we're both right.
I should try it again. After the C-54.