The Parker 51 is both highly collectable and eminently useable at the same time. The Parker 51 Fountain Pen - A Brief History.
Parker 51 Archive - Page 1
Ref. 1271
Classic trio Parker 51 ballpoint, fountain pen and pencil, black with lustraloy caps, 14crt medium nib, aerometric filler, very good condition, pearlised jewels to caps, circa 1960s, (very good), made in England. Sold

Ref. 977
MKII Parker 51 Custom fountain pen, gold filled cap, burgundy, 14crt medium nib, pearlised clip jewel, aerometric filler, retailer chark marks, boxed with original guarantee, English, 1960s, (near mint). Sold

Ref. 1050
Parker 51 Custom fountain pen, teal blue barrel and satin lustraloy cap, 14crt medium nib, pearlised cap jewel, aerometric filler, no dents, dings or scratches, inked but excellent, c. 1960s, English, (excellent). Sold

Ref. 1139A
Parker 51 Custom fountain pen, burgundy barrel and satin lustraloy cap, 14crt medium nib, pearlised cap jewel, aerometric filler, no dents, dings or scratches, original retailer chalk marks, inked but mint, boxed with original instructions and warranty, c. 1960s, English. Sold

Ref. 1175
Rolled silver and burgundy Parker 51 fountain pen, 14crt medium italic nib, pearlised cap jewel, aerometric filler, no dents, dings or scratches, inked but excellent, boxed, c. 1950s, English, (excellent). Sold

Ref. 897
Parker 51 Custom fountain pen and clutch action pencil, gold filled caps, grey barrels, 14crt fine nib, pearlised clip jewels, aerometric filler, English, circa 1960s, (excellent). Sold

Ref. 893
Demi size Parker 51 Classic fountain pen, satin finish lustraloy cap, dove grey, 14crt medium nib, pearlised clip jewel, aerometric filler, boxed, no dents or scratches, USA, c. 1948, (excellent). Sold

Ref. 996
Parker 51, rolled silver cap with black barrel, 14crt medium nib, pearlised cap jewel, aerometric filler, no scratches or dents, unmarked in all respects, uninked and boxed example of this rare 51, English, (mint). Sold

Ref. 988
Parker 51 Classic fountain pen, satin finish lustraloy cap, teal blue, 14crt medium nib, pearlised clip jewel, aerometric filler, boxed with instructions and guarantee, unmarked in all respects, English, 1960s, (excellent). Sold