Need help with jersey previews

I'm having trouble with jersey previews for some classic teams that I'm trying to create. Since the game already has classic jerseys and their previews, I'm just renaming existing jersey previews. The jerseys work fine during gameplay, but I can't get them to show up at the jersey preview screen.

Here's an example. I'm, trying to make a 72 Lakers team, so I take the 1971 retro jerseys and previews for the Lakers and rename them using bigGUI.

For the previews, I extract jerseys~ll~ll_c71h.big and jerseys~ll~ll_c71a.big form jerseys.viv and rename them to jerseys~ly~ly_c71h.big and jerseys~ly~ly_c71a.big.

Next, I open up one of the files (let's say jerseys~lx~lx_c71h.big), and see:
ll_c71a.apt
ll_c71a.const
ll_c71a.ebo
ll_c71a.fsh

Still in bigGUI, I rename the four files to:
lx_c71a.apt
lx_c71a.const
lx_c71a.ebo
lx_c71a.fsh

I close the file, place it in the sgsm folder, and fire up the game... but no preview...

Can someone tell me what I am doing wrong and the correct way to rename (or repack) the preview files? Thanks in advance.

Live 06 patching section. Theres a sticky there on portraits tutorial.

Problem solved. I didn't edit the ebo files. Thanks for the help!