I know of 2. One is right across the street from Threads and Flirt...its in a green house. In uptown....
I went one time. Its not my fav vintage store but its pretty good for Dallas. I can't recall the name.
I think there is also one...on Maple and Oak Lawn or that area. There is an Exxon station right there...and if you are facing the Exxon...turn to your left and I think there is something right there too...
I hope that helps. Also...try lower Greenville...there is alot of stuff there.