Several of the earliest UP patterns (like Overland Route and Ogden) have been counterfeited. Reportedly they were well crafted forgeries. Our best advice is to use care when considering items in these patterns.
Zephyr pattern silveware
The B&O Musem had a batch of reproduction UP Zephyr silverware produced (along with silverware from other RR's). This probably only applies to the backmarked items, and those that did NOT have the Winged Streamliner logo. The telltale sign is a large number "1" or "2" stamped on the back of the handle. In any case, the large number half way up the back of the handle is the sure give.
(Note: The use of the word "counterfeit" to describe this china is not meant to imply that it is "good" or "bad" - for our purposes, the intentions of the counterfeiters are irrelevant. Authentic dining car china was made to be dining car china, counterfeit china was made to look like dining car china. Well done or not, it is not authentic dining car china, and if it is not clearly marked as a reproduction, then it is counterfeit.)