fundekals seems to know something I've never seen before. From their site..."These decals are designed to make your Tamiya F4U or FG-1D Corsair look more authentic. Photographs of carrier-based Corsairs in 1945 show the ammo cans were rarely returned to the correct position. This is why the insignia on the left upper wing seldom appeared complete. Our decals assist the modeler in replicating this phenomenon" This is a link to the decal instruction PDF (these guys don't provide instruction sheets with their decals to cut down on cost) http://www.fundekals.com/images/CorsairAmoCans/F4U_Ammo_Can_Inst.pdf
Now I'll be looking a bit more carefully at Corsair photos