nickel silver tea service

I bought this 3 piece set of antique nickel silver tea set from a mobile antique seller that was unloading antique stuff on the table by the sidewalk in Philadelphia for $65.00. It is in very good condition without any dent and around 4 1/2" tall each one is a goblet, a creamer, and a cup with two handles and a lid. The bottom is marked "nickel silver with an eagle and a letter JW in the center of the eagle. There is another circle below the eagle with a cross inside and an inscribed symbol SUT/x. I did some research on it and the only closest information I found is that it is around 1854 and attributed to John Wanamaker. I am not entirely sure about it though because the mark on the site where I was searching is a little bit different from the mark on my items. I would really appreciate any information you could provide on this items. Thanks you very much in advance.