hi mike, looks like a major meltdown there, i would imagine the mark numbers refer to could be for the crankshaft regrinds, 1,2,3, would probably mean there are 3 oversize bearings that you can get ,thats 3 cranshaft regrinds ,i doubt using fine emery paper would take enough off the crankshaft to worry about putting in an oversize bearing, certainly pull the rod cap off and inspect the crankshaft for grooves, you may be lucky enough to not have any damage but i doubt it, the number 2 you refer to could be no two piston, you can see if its number 2 by looking at where the piston ,conrod is on the crankshaft, i am not saying for sure thats what all the numbers mean but sounds like it to me, dont know if you can buy just one bearing you may have to buy a set, then you might as well put a new bearing in each one, if you do dont get the bearing caps mixed up do one at a time, also make sure the bearing cap goes back on the same way it came off, mark the cap so you know .hope you get it going.
cheers fergi