This is a 1951 Parker 51 Aerometric fountain pen in Burgundy, with a stainless steel cap and a Parker "factory" 14k gold Broad Stub-Italic nib. The pen has been restored, which included a complete disassembly, a thorough cleaning, an overhaul of the filling mechanism, ink flow adjustment, nib tune-up, and a gentle polish with a soft cloth (by hand). I work according to current "best practices" in pen restoration and I use high-quality replacement materials. Though I restored the filling mechanism, you might be interested in knowing that I kept the original breather tube, as it was in a pristine condition.
Parker 51 was, truly, the world's most wanted pen. Thanks to its timeless design and extremely high quality of materials and craftsmanship, we can still enjoy this amazing pen, particularly if restored well. The vast majority of Parker 51s come with Fine or Extra-Fine nibs, though Parker did offer a broad array of special-order nib grinds. This particular nib is a a very rare Parker original "factory" Broad Stub. The distinction among different types of italic nibs is relatively recent, so the terminology can be a bit confusing. Therefore, the best way to define such a nib is by empirical testing (i.e., writing) and stroke measurements.
The nib writes a 1.2 mm downstroke and 0.2 mm cross-stroke, which, according to current nomenclature, puts this nib in the vicinity of a "cursive-italic." What it means, in everyday writing, is that you can get very good line variation, but without the sharpness and small "sweet spot" associated with "formal italic" nibs. This is an extremely smooth nib, ground in a way that allows making confident strokes in virtually all directions without ever catching the paper. The corners are slightly rounded, but without sacrificing line variation. It is, therefore, an ideal nib for anyone wishing to write a variety of styles, ranging from formal italic, through cursive italic, business cursive, and can even be used as a dedicated "signature" nib.
If you take a closer look at the close-up photograph, you will notice the incredible precision with which this nib was made. Though Parker had excellent automation in place, a lot of the steps in the making of the 51 were done by hand, including nib grinding and polishing. Every nib was submitted to a meticulous process of quality control, including machine testing, visual inspection, and writing tests by a team of experienced technicians. What you can also see in this photo is that the nib is in fantastic overall condition, virtually as good as new.
Cosmetically, the pen is also in excellent shape, without any flaws or defects. The color is deep, rich, and vibrant, the material smooth with a nice semi-gloss type of finish. The cap is in equally great condition.