The 199 Australian is one of the brass dip pens made by Esterbrook, with the Colorado pens being the most widely known in this series. The Australian is a highly uncommon pen. I've found listings for it in the following references:
1876 Price List
1879 Trade Price List
1887 Anderson & Krum catalog
Esterbrook made several versions of this style of pen including the various Colorado pens, the Australian, the Indestructible and the Arlington. They also made a "German Silver" (nickle silver alloy) version called the Silverine.
I don't find any evidence that the Australian was ever gilt. These brass pens were originally quite shiny and looked a lot like gold pens (hence many of them having names reminiscent of big gold strikes, like Colorado and Australia), but could also become more tarnished. These were marketed as cheap versions of the gold pens which wouldn't corrode like steel. Some could have been gilt, I know some Colorado's have been, but the listings just mention "Golden" which is their term for brass, vs. "Gold" which is what they say when it's gold plated. What could be happening is that your pen still has the original varnish intact on spots and what you see there is what the pen originally looked like. Or it was gilt and the gold has worn off in spots. (but that would generally be in a more consistent pattern of wear)
Unfortunately, they were not flexible, like steel or gold, but they could be repaired by just bending it back into place. The 1877 listing of the #307 Indestructible says:
"Made of Composition. Can be beat in all directions and restored to shape for use again. A good pen for "Curb Stone Salesmen" and Prize Packages." (curb stone salesman is an old term for door-to-door salesman)
These curved imprints generally mean an early pen, but that's not a guarantee on a brass one. Regardless, because they don't seem to be sold after the 1880's, it is still considered relatively early, and it is very rare.
I'm assuming you sent a photo to Phil. I'm helping him out by creating the second-generation of the web site. (that's why I have so much info about Esterbrook pens).
Here is a comparison of a standard-sized Colorado against the quite large Arlington (also a very rare pen in this series).
Hope this helps you learn more about your very nice pen.
Edited by AAAndrew, 09 December 2019 - 21:35.