I have done a lot of searching and can't seem to find anything on just what I'm looking for. What I want to do is move a Sim from one computer to another and keep him completely in tact (hair, clothing, custom eyes, skin, patterns used, etc.)

How would I go about either preserving all of these things while packaging him (I think custom content used to be automatically packaged with the Sim but isn't anymore?) or, if nothing else, detecting everything that is utilized by this Sim so I can locate the files and move them all manually/individually, please?I'd greatly appreciate any help anyone can provide. Thanks.

How much of your CC is Sims3packs? They should still package with your sim. It's just package style that doesn't.
I was going to suggest packaging him in a lot and then scanning it with Delphy's tool, but I'm pretty sure the packages wouldn't be in that either.

A time-consuming way would be to make a new neighborhood with a copy of your sim in a lot. Then remove all the relevant CC except what you think he might be using. Clear the cache. Go back into the game and see if you were right. If not, change the items that were wrong and repeat until you have it all. Now put your CC back in and get the real copy of the sim packaged with the list of what you discovered him using. (relevant CC means that if you -know- he's got Maxis hair, you can leave your CC hair alone. If you know you used body sliders, leave them in. etc.)

Moving to Discussion as this isn't a Game Help Issue.

I might be able to figure it out that way sooner or later, if I can find the time, but I have so many, the file names are nowhere near self-explanatory, nor are the thumbnails in-game... If anyone does happen to know of a way I can at least discover file names while WITHIN the game, then, that would be enough. Thanks.