I have a few of the "Gold is BACK/Gold Filled pens" which are collectively known as "Coronet" pens/pencils. I finally got my hands on an actual jewelry store Coronet four days ago.
My best guess is that it was the model 17730 pen which is described in some of the surviving advertisements from that era. The ads were black and white, so some things are uncertain.
It is the Gold filled cap with the square Pyralin accents with the black celluloid (Pyralin) body with the transparent ink view window. It had the self-fitting-point (the adjustable nib with the silver
colored slider block) for adjusting flex. Another indicator the Jewelry Store version is the Gold cap at the butt end of the barrel. Also note the curved wicking element sticking out of the section (which indicates range of years of production). These are similar to the part used on another well-known brand of pen.
It was MUCH easier to get apart than the all metal version of the pen. I almost felt dirty it was so easy. The pen was disassembled, cleaned, the #18 sac was replaced, shellac cured, and re-assembled. The section fit firmly, but without the trauma of it being shrunk celluloid over un-shrunk Hard Rubber.
The nib flexes to about 2.25mm, which is about on par with other examples of the self-fitting-point pens which are out there. The view window has darkened to a deep amber, but
shows no sign of cracking or crazing. I will have to do some light plating work on the common wear points on the pen, but that is to be expected. Step one is always to get the pen
mechanically sound, before you work on the pretty stuff. I am just glad I won't have to engrave obliterated (worn) lines first, that is tedious work.
Four pictures... 1. as it was advertised, 2. once mostly disassembled, 3. Sac replaced and the shellac curing before assembly, 4. assembled, filled, and with some test writing with the pen.
Edited by Addertooth, 24 December 2019 - 21:17.