Sheridan Silver 5 pc. tea set

I know this set was purchased atleast 20 years ago by my father but it may have been purchased before then. He bought 2 tea sets for my mother, one when they got married in 1971 and a second set in the early 80s. I have tried researching on the internet to find a pretty good idea of what the set is worth but so far I haven't found any information. Tea set is in good shape, needs a good cleaning and the tray itself is a little scratched (possibly would come off with a good cleaning). No dents in the set. Any information would be greatly appreciated. Also, I am not sure if it should be considered a 4 piece or 5 piece set, I put 5 piece because the lid on the sugar bowl is detached while the lid on the tea pot is attached. Thank you. Any suggestions on a place to look online for more information about the set will be greatly appreciated.

Fair