After much dithering about worrying about how to drill the 1/4" and 3/8" holes thus the landing gear support blocks and belly skin (whether to step drill with a bushing or not) I bought a long drill bit for each hole size from Lowes and lubricated the shank with Vaseline so that it would not bind in the block and then just drilled full size in one shot thru the block hole into and thru the belly skin, doubler and gusset, while my wife backed-up the opposite side with a two by four. This worked well and was easy. I used my electric drill since I don't think my air palm drill would have the power needed. Only the aft two holes are accessible, I will drill the forward hole when the skin is removed using the block, bolted to the skins thru the two holes, as a drill guide as Glen did. Note: on closer inspection I see that there is some scoring of the drilled bores. I will polish these out but for the forward holes I will use WD-40 as a lubricant.
