This Vibroplex Junior with colored base, is a 1938 RARE Vintage Semi Automatic "Bug" In 1934, Vibroplex began advertising the ?Martin Junior,? which was an Original on a 3? base instead of the standard 3.5? base. Except for the base width, everything else was the same as on the Original. However, Vibroplex had apparently been making the same bug on special order since about 1920. The early ones were called the ?small-base Original? but to almost everybody they?re a Junior.Later on, the model was called the junior-model Vibroplex, and it was discontinued about 1939, when the Zephyr, Champion and Deluxe Vibroplexes were introduced. Late Juniors have a black crackle base, some with pinstriping, and it?s possible that nickel-base Juniors exist, although none are known to collectors. Colored-base Juniors were never advertised but were made special order. This one is silver with a crackle finish. I am not a key expert but it does look original. The serial number is 111130This Semi Automatic Key or "Bug" is very rare! This unit will be a great addition to any collection!