Model 111 was initially introduced as "Pelikan Gold" in 1930. It was characterized by cap bands and sleeve(1) in 14 carat gold. For other parts, it was same as model 100. The hallmark "585" can be seen on the top of the overlay (arrow). Barrel width without buffer sleeve; 11.0 mm, barrel width with buffer sleeve; 11.7 mm, barrel width with gold overlay; 12.2 mm. The width is almost the same as 100s. So, it does not look plump.
Note;(1) Pelikan allegedly used to put a “buffer” sleeve onto the barrel and shave it down so it can accommodate the overlay tightly (Fig.2). I also have seen several pens with sleeve under sleeve. But, not all of the metal overlays have buffer sleeve under them(Fig.3).
Fig.1. Pelikan 111 (ca.1933). Gold overlay and a “buffer” sleeve (arrow head) under it.
Fig.2. Pelikan 100 (ca.1935). According to Rick Propas, he found this yellow sleeve shaved down under metal overlays. Presumably they were seen as disposable.
Fig.3. Pelikan 100 (ca.1933). By courtesy of @DerMarsianer.