Taking models & Textures from BC Client and importing them into PREBC client|need hlp

[yomamasman]

Hello I am and have been using mywarcraftstudio to model edit items such as weapons armor,
even stuff like creatures, doors, ect. But recently I have been trying to import BC items such as shoulders
weapons gear ect.

I import the M2 and BLP files required (as i normally do when im model changing something in my prebc client)
renamed the directories so they would overwrite what gear i have on like i usually do, but when i put the BC M2's and BLP's in the exact
place of what im changing, they end up invisible when i try to look at them.

For instance I switch my T2 Hunter gear to look like T3 no problem (all within the pre bc client)
then i extract the tier 4 from the BC client in the exact same method as i use for my previous swap,
and when i try to switch it to t4 its invisible,

am i missing something? in BC is there more than just M2 and BLP files i have to bring over?
When i use this method with anything in the prebc client it works fine,
but m2's and blp's from the BC MPQ files dont seem to work in the pre bc client.
anyone have any wisdom on this?