This is a surprisingly big part of my life, and is my third 10,000 hours skill (google that up, please, that's a skill too) of a pretty busy lifetime so far.
A typical sort is like the one above - parts from one or two machines, many of which will be repeats (and therefore will have stock numbers to assign) and some of which will be unique, or the sort of item that needs a separate image as condition varies so much on some things..
Here's a basketful I sorted and photographed this Summer. Odd feets (nothing unique in here, I hope..)
Sorted into types, and some needing testing put aside. I test everything I can on a 1928 Singer treadle.. (That's for Low Shank feet). I also have a High Shank Singer (31k15) treadle industrial, and when I have Slant Shank machines here I test everything madly on those too..
I lay them out in sorts, count and catalogue and put away in tins..
Not a job for the unfernickety..
I'm always happy to ID odd feet and attachments, please email me with an image
Oh, and here are the other things you almost always find in sewing machine drawers.. Yes, that's a razor blade. Watch your fingers..
I commonly find three different (and incompatible) sorts of bobbins in the drawer too..
Usually the suspender buttons are singles..