I think the main hold up to something like that would be the fact that the big end of both rods ride on the same journal. In many "Autozone Rebuilt" engines you will find similar stuff. Maybe .010 undersize on 1 rod journal, another 1 standard, and then another maybe .020 undersize. If it were mine- I'd turn it down to a uniform size.
Besides, how do you gaurantee that journal is round after you have worked it w/ sandpaper or emery cloth? I've seen that done on $1000 dollar used cars, and they ran for a while after it was done. All I know is the ride you could take from that rod seizing to the crank doesnt sound like it would make for a good race weekend. I'll bet somebody makes undersize rod bearings, or could make them. It may not be any cheaper than a new crank at some point, but they cant be that hard to make.