The car was built between the years of 1904 and 1916, in Italy as the Guy and in France as the Le Gui. It was also known in England as the Millard-Le Gui after one of the importers who handled it.
The cap is cast brass with a copper insert and has an OD of 2.680” X 1 1/8” high. It is 2 ¼” across the flats and the OD of the threads is 2.160”