Not all are WM Rogers pieces. It appears the tea pot, coffee pot, sugar bowl and creamer bowl are. The tray and pitcher are not original to the set from what I can tell.
See photos. The tea pots and sliver platter are stamped. I don't see a stamp on the sugar bowl and creamer but they came with the set and appear to match.
The hinge for the lid for the tea pot is broken.
I purchased this used, and I used it as a display. It needs cleaning.