I'm not sure if this is in the right place...but I could not find any other thread to attach it to. I just made my first mesh, using Brianna's tutorial, and it came out beautifully....I took the "clam digger" female adult pajamas and made the sleeves longer, the pants longer and wider and the top now comes farther down over the rear end and it is absolutely great except !!! I somehow seem to have changed the original into my new version because that is all that now shows up in Body Shop. Can anyone tell me where I went wrong and how to fix it?

Wish I could help more but all I can offer is this link
http://www.modthesims2.com/showthread.php?t=43338

A tutorial on making a hair or clothing mesh as a non-replacement. I don't know if it will help since you've already accidentally replaced the default mesh but hey I try

Maybe try deleting the new mesh.