The Striped Duofold (also known as the Duovac) was released for sale in 1940 and the production ran until 1948. There were 8 variants of this design, most easily distinguishable by the combination of the colour and the cap. This variant is the Junior model, as can be identified by the two narrow cap bands and the clip.
The Duovac was offered with a two variations of the vacumatic filling systems. This one has the aluminium “Speedline” filler (shown below), but others had the standard Vacumatic. Two of the variants use a button filling system. The details of all of this can be found on the “Duovac” page at parkerpens.net and on Richard Binder’s page.
This particular pen was made in the first quarter of 1941. This is indicated on the barrel using a code that was stamped into many Parker pens, shown in the photo below. Notice the “1” (indicating a production year of 1941, since the Duovac was not made in any other year that ended with a “1”) and the three dots. The three dots are the “first quarter” indicator. One of the dots would have been filed off the stamping tool for the second quarter, leaving two. Another dot would have been filed off for the 3rd quarter, and the last dot removed in the 4th quarter (leaving no marks on the barrel).
The 1941 Duovacs introduced a transparency feature (slightly visible in the photo above as an amber glow through the barrel). This was called the “Full Television” feature – since that was a new technology at the time…
Total weight: 14.3 g
Body weight: 9.2 g
Total length (not posted): 120.0 mm
Total length(with cap): 131.4 mm
Barrel max diameter: 11.4 mm
Cap max diameter: 12.6 mm