The Parker "51" is legendary and remained in production from 1941 to 1972. Even longer if you include the later Argentina production years. With anything made for 3 decades the pens went through several design changes. This is a 1st generation pen with white jewels on the cap and blind cap. The original, and by some accounts, the best. Buckskin Beige is one of the less common colors.
The condition of this pen is very good. The cap has no flaws, dents or plating loss. It is engraved WH. The filler is in excellent condition. The diaphragm has been replaced and the pen fills as designed. The only flaw in the Lucite is a tiny notch at the shell opening for the nib. It is not a crack and will not propagate.
The nib writes a fine line (perhaps extra-fine if you are accustomed to modern, western nibs). It has been adjusted to write wet & smooth.
Length Capped - 137 mm (5.4”) Uncapped - 126 mm (5”) Posted - 154 mm (6”). Diameter Cap - 12.4 mm (0.5”) Barrel - 11.8 mm (0.47”)