I collect a broad range of milsurps and am helping out a local shop that just got in a large consignment of guns and a pretty big mixed-bag of parts (mostly post-CW era and some WWI/II) that need sorting and ID'ing. Most of the stuff is separated fairly well by gun type, but there's still a lot of loose parts with no ID. How do you guys go about IDing parts? Specifically looking for dimensional drawings or specs on the common things like screws, barrel bands, swivels, perc hammers, etc that all look closely alike. I look at the online stores like Liberty Tree or Simpsons and marvel at the descriptions they have and wonder if they don't have an army of researchers...

Thanks for any help you can provide...