First, a couple of moderation things - I deleted your duplicate post; there were no comments on it. Also, you can attach multiple pictures to a single post. There should be a button under the first upload slot for adding another attachment.
Second, that is a lovely corset! If you haven't already googled the stamp, that is always a good place to start. It looks like a late Victorian or early Edwardian style. If you can get a photo of it on a dress form (or pillow), that would make it easier to see the shape and date it. You can also go to an online corset museum like Laracorsers (currently undergoing renovations, it seems), the V&A, or the Met, and look for corsets that have a similar cut. That can be the best way to date a mystery corset. Good luck! Let us know if you find anything out!