40#, 40", 19" draw? Heck yeah! What do you think the Sioux were shooting buffalo with? Don't let some of the sinew tribe tell you that all the Sioux bows were backed with sinew, plenty were just bare wood bows.
If you backed a 1 1/4" hickory board with linen, silk, or even cotton fabric, you could do a bend thru the handle bow easily enough. Don't even worry about flipping the tips any. If you were to toast the belly, it wouldn't even take up much set, I bet.