Yup. I got a better idea. Get small blocks of 3/4″ plywood and drill them on a drill press to make “temporary risers”. Insert them to drill the holes (drilling right through them into the trailer bottom. I am at the same stage you are. The teardrop is upside down and I don’t want to put it on the trailer, then turn it over again. That’s a big hassle with an big risk of dropping/ damage. As it is I rolled the shell carefully on a thick carpet to get it upside down. My trailer is too far together for me to be inclined to disassemble down to a manageable section to lay on the camper. So this is how I may drill fill drill my holes: Put teardrop on trailer to mark holes. Elevate the teardrop somewhat on blocks (on the floor), roll trailer forward a little bit; drill the oversize holes while laying under the teardrop; fill the holes; roll the trailer back in position and lower the teardrop in place and redrill the holes. Even though I got the big wheels, the may not be enough room to crawl under there, so I may have to elevate the trailer and the teardrop somewhat to do this. I like your method theoretically, so maybe I can beg enough muscle to set the whole trailer on the upside down teardrop – if the hatch bezel/roof can take the combined weight????? But I am worried about retorquing the trailer assembly bolts to remove the tongue to reduce weight.