Naturally. the vast majority of Roman sculpture and artifacts reside in museums in Europe and along the Mediterranean. However, the University of Pennsylvania Museum of Archaeology and Anthropology holds an object of keen interest to Roman military equipment studies. The Puteoli block was carved during the reign of Domitian and depicts his Praetorian guardsmen. One carries a shield emblazoned with a very nice vine and scorpion design. The scorpio, birth sign of Emperor Tiberius, often appeared on Praetorian equipment. Tiberius was so honored because he allowed the Praetorian camp to be built in Rome, centralizing their power. No other Roman legion appear to have used the scorpion emblem. A color interpretation of this shield blazon appears in The Praetorian Guard by Boris Rankov.
The above photo of the other half of the Puteoli block is courtesy of Jasper Oorthuys. It is housed in Pergamon Museum in Berlin. Thanks, Jasper! Images of both these sections are rarely found on the internet, so I definitely appreciate your contribution!
For a detailed study of this monument see Flower, Harriet. "A Tale of Two Monuments: Domitian, Trajan, and Some Praetorians at Puteoli" in American Journal of Archaeology, Vol 105. No. 4, October 2001. pages 625 - 648.