those holes are also on the SB2C
this was posted today www.network54.com/.../Had+enough+F4U2+yet-
look at the third photo down the page,,,,,,,,but, instead of a crane, I thought I remembered seeing a stand that went under there,,,,,sort of like the Skyhawk and Sabre rear fuselage dolly that carried the back end around when doing engine changes,,,,,,,I know that in Mustang gun sighting there was a stand underneath
I also don't think the holes go all the way through, using a "pipe or rod",,maybe they did on WW II aircraft, but, later on they were reinforced fittings on each side as separate items,,,,,see Phantom "hook points" for an idea of what I mean
edit,,,,,,,,fourth photo down, sorry,,,,,,,,,,,,and it is indeed a pipe or rod on that Corsair,,,,,,but, later on with more modern aircraft, they sure weren't
and just now in the middle of the night I realized that those holes could also be the mounting points for the suspension gear used to hang WWII and earlier aircraft from the ceiling on the hangar deck
Rex