[mertchicken]

I was wondering if it was possible to edit shoulder armor models so they’ll only display one side?  If so, is it something someone could explain or maybe point me in the right direction to figure out on my own?

[Atraxian]

Might not be the answer you were hoping for but some armor pieces have asymmetrical shoulders, you might want to look at one of them and compare it to other models.
One of them is item number 23277, Lieutent Commander's Lamellar Shoulders

EDIT: I'm assuming you are talking about WotLK 3.3.5a
I took a little time to look at the Item.dbc and ItemDisplayInfo.dbc. In ItemDisplayInfo.dbc you have 2 different columns used for tho different models for right and left shoulder piece, so you can mix and match the models you want to display.
Have you tried using only 1 model and leaving the other column empty?

[mertchicken]

Thank you, I was able to get it to work.  After I edited the DBC and patched the client it worked great.