I must say I'm really impressed. I bought a used wedding gown at the Brides' Project that had a noticeable stain on the train. I was worried because the stain was old and the dress had lace and beading all over. Also, the stain was brown/yellow colour (food or wine I think), which I hear is very difficult to remove.
Golden Hanger Cleaners was able to remove the stain as well as the black dirt on the train without damage to the dress. They also did a wonderful job with pressing (or steaming?) the dress. The dress now looks brand new.
If you're looking for someone to preserve your wedding gown, I recommend you check them out.