|Descr.||Colorado (gold plated)|
|Mark 1||R.ESTERBROOK & CO'S|
|Mark 3||Nº 1|
The Esterbrook Project describes this nib as having a body that tapers up from heel to shoulder, then ending in a sharp point. A circle vent hole. Gold toned. The Project further notes, "This pen came into production during the early days of Esterbook's history. Later, this pen had an embossed "G" added to make it the #1 G Colorado pen."
AAAndrew's Steel Pen blog explains that the "Colorado" is a particular shape of pen. "Similar to a taper shape, but very shoulder-heavy, and a flat profile, as seen on the various Colorado pens from Esterbrook and others." (For an example, AAAndrew links to a #2 Colorado from The Esterbrook Project.)
There are no additional versions of the Esterbrook #1 Colorado Pen in the Chappy's Nibs collection, as pictured below (gold-finish).
Click any image for a full-resolution photo: 2200 x 640. The image with the ruler is 2300 x 1196.