Dita Von Teese velvet dress - transparency issues

Hey guys ! I need your help ! I'm working on this beautiful dress for my Dita Von Teese sim and have used a bridal dress with a transparent skirt as a base to get that split dress. Unfortunately, as you can see, I still have some transparency issues on the skirt I can't avoid if I want to keep the split. I don't have enough time to work on Blender, but if someone knows what to do and wants to fix that for me, I'd be grateful ! Thanks a lot !

You can get the dress here : simfileshare.net/download/1190555/

The mesh I used : www.thesimsresource.com/downloads/details/category/sims4-clothing-female-teenadultelder-everyday/title/bridal-dress/id/1326128/