That is really a nice find, very beautiful. It is a bit difficult to date it without seeing it displayed on a mannequin or human form, in order to the way it is cut and how it drapes, etc. We could also help more if we see the other side of the garment. Are you showing us the back in the photo? Technically it is not a blouse, but looks more like the waist or top of a lovely dress or evening gown. Without seeing it on a human form, I might estimate it dates from the very late 1890s to the early 1900s but not much later than 1904-1905. It is really nice to see the Lord and Taylor name woven into the Petersham belting. I have not seen that before.
Are there tiny seed beads or marcasites sewn onto the lace? I would not be surprised to find this is a copy or adaption of a French Haute Couture gown. The roses have an Art Nouveau style to them.
Other VFG members will likely come along and add more information.
Thank you for sharing your treasure with us here at the VFG.