At the peak of the celluloid period the Diamond Medal pen company produced their Diplomat pen, an oversized model using multiple layers of celluloid material. This one, ca. 1929, features black and white end caps on both the cap and barrel and a beautifully preserved black and pearl body. Although not one of the big four pen makers, this Chicago pen company produced some of the most striking and colorful models. Only the gripping section and the feed are made out of hard rubber.  It does not and probably never has had a bladder inside which is likely reason that the color is as it is. One can be installed or provided outside the pen on request. The near-mint #8 nib shows a patina which reinforces its remarkable original condition. This is a scarce pen in a highly collectible condition.