The only Samson I have seen have been figurines, imitations of Chelsea, with anchor marks, rather than snuff boxes.
However, when I first looked at your piece, I thought it looked very like Limoges, and was surprised to see the Sevres mark on it. Have you seen this list of fake Sevres marks?
http://users.skynet.be/rutrene/marks21.html At the bottom of page 1, it states that Limoges did have pieces decorated at Sevres, and also used an imitation Sevres mark, so that is a possibility - the deep yellow is a typical Limoges colour, as is the use of the bunched flowers. However these are also typical of Dresden Deutsche Blumen patterns, so again, interesting that some German makers also used the Sevres mark.