On my Dago there is one place I did reinforce and that is the blocks in the wing where the LG mounts.. This seems to be the weak spot on all WM 40 size Mustangs... All I did though was remove the LG and paint the area with epoxy... Never had a problem there
after that.. I have seen some guys reinforce the center section of the wing etc and some don't... Doesn't seem to matter.. I have never seen one com apart there... I think it is more of a feel good thing..