These pieces are marked with a bright red PRR Keystone logo - dead center on white china. The red is too bright compared to anything used by the Pennsy. These are not so much counterfeit pieces (because they copy no real pattern), but rather toys. Alas, unscrupuous antique dealers often try to palm these off as "vintage" pieces. They often site glaze crazing as proof of their age, but it more closely reflects that such pieces are truly cheap imports. They must have been made by the shipping container full, as they exceed the level of common. The only piece I recall seeing was an individual creamer, but it is likely that other small pieces exist in the set. They truly have NO value, except as toys or to dupe the unknowing.
Always remember to check the backstamp, as this pattern has been reproduced. Most is well marked as such, but some seem more sly. Look for vintage Fraunfelter (Ohio), Scammell, Shenango, Syracuse or Warwick backmarks. Particularily watch for Sterling Lamberton pieces - they sure look aithentic, but apparently are not - the date code, if present, indicates this.
(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 such, then it is counterfeit.)