Both the B&O RR Museum and the EL Dining Car Preservation group have reproducted Lackawanna Cromwell silver flatware. In the case of the B&O Museum items, the telltale sign is a large number "1" or "2" stamped on the back of the handle. In the case of ELDCP, the telltale sign is that the items were manufactured by "World Silver" - not IS as were the authentic items.
Sierra pattern silveware
The EL Dining Car Preservation group has supposedly reproduced Lackawanna Sierra silver flatware. They seem to claim that it was made by Reed & Barton, which might make it difficult to distinguish from authentic ware. Caution is advised when purchasing this pattern of DL&W flatware
Zephyr pattern silverware
The B&O RR Museum had a batch of reproduction Lackawanna Zephyr silver flatware produced (along with silverware from other RR's). The telltale sign is a large number "1" or "2" stamped on the back of the handle.
(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.)