Magic Tea Party Blouse sizing?

So, I recently purchased a Magic Tea Party blouse second hand and it's absolutely AMAZING. I've decided I would love to purchase more from them, but I'm running into a bit of a problem. The blouse I purchased was said to have been tailor made for the previous owners measurements, however, the tag on the blouse actually has an S on it. Now, I know I'm not a small, and according to their size measurements, their XL size looks like it would fit well everywhere except the bust, as its pretty much my exact measurements (with a little extra room in the waist, which is always a plus). So basically, since I don't actually know what size my blouse is, can anyone with any of their blouses please let me know if they actually run true to size or perhaps a smidge larger? I'd hate to have to get them all custom made just for a couple cms of wiggle room for my stupid boobs.