IIRC, there are some markings on the SN pad of the block that have special symbols for any undersized main or rod bearing used in the factory. BTW, do you have a dial caliper? If so that will be accurate enough see if the journals are all standard; any journal being tuned down .010" or .020" will be obvious with a caliper. (Checking actual wear is best done with a micrometer.)
I can't say I ever paid a whole lot of attention to the bearings I take out and toss, besides the STD markings, so can't be of much help there.