Cooling fans

That's nice if you can do it. The easier way to match them up with a buyer is to offer them up with all the info you can, and the person looking will know what they need.
If there is a number, post that in text and photo.
At least one photo for each where the leading tip of the blades are shown. Some had notches for more clearance with the bubbletop radiators.
Measurement of the diameter is really helpful because the FSM has that info, so even without a part number, the buyer will be on the lookout for that.
Ditto the number of blades, and the blade depth.
To measure the diameter on the fans with odd number of blades, probably best to work from the radius. Within plus/minus 1/8" should be enough.