Finding the sources that various companies used is one of the more difficult areas of pen research. We can sometimes tie a pen brand back to the retailer who sold it, and sometimes tie the pen back to a manufacturer, but getting the next level back to the source of parts is often much harder. Smaller pen manufacturers seem to have often purchased parts from the same suppliers, especially things like trim or metal fittings.
So I was quite pleased to discover the following article, "Waterloo Way Keeps Winning" from the Waterloo Daily Reporter, Friday, December 10, 1909 p.2, about William A. Welty, of the William Welty Pen Co., and his travels east to build the market for his pens. The article quoted The Lancaster News of Dec 7th, from Lancaster PA:
QUOTE
"Mr. William A. Welty of the Willam A. Welty Co., with headquarters and factory in Waterloo, Iowa, one of the busiest manufacturing cities in the west, is in the city [Lancaster PA] today transacting business with the United Novelty Works, a large concern manufacturing gold mountings for fountain pens, etc."
So now we have a name for one source of the metal parts used on Welty's pens, and most likely other small pen makers. So far I have not found anything else about the firm, but this shows us one source of these pen parts. It also shows the extent to which a moderate-sized midwestern manufacturer would be willing to source parts from hundreds of miles east.
John