Ghostrider,
You can sort it by opening your .mis files and scrolling down to near the bottom and taking a look at all of the objects in your missions. Here is an example:
[unit_type.13]
type_id=4339
unit_family=4
name=inf_AtlanticWall_Bunker9 <<--Stitz Atlantic Wall Bunkers
[unit_type.14]
type_id=4386
unit_family=4
name=inf_predam1 <<-- Woza smoke effect
[unit_type.15]
type_id=4409
unit_family=4
name=inf_tents_round <<-- Stock MS round tent
[unit_type.16]
type_id=4550
unit_family=4
name=LDW_generic_1_med <<--Lindsay Watt tree
Once you have the list in front of you, you can then determine who made them a little more easily.
When I make missions to upload, I generally keep a log so that when I write the readme file, I can then write it and include everything. Then when you list everything, list them by packages and not individually. Ie. AF=Midway or LDW trees, etc.
Writing a good readme file can actually be harder than making the missions if you add a lot of objects.