One of my dubious areas of achievement is in researching and presenting historical tours of Philadephia, and based on what I know, my guess is that the Junior Screw Association was a tradesman's union, and that object in the illustration was a tool of the trade.

Philadelphia was once known as "The Workshop of the World" because of the size of it's workforce and the diversity of it's manufacturing industries. At the turn of the 20th century, more than 700 companies employed 60,000 workers in textile manufacture, and that was only a quarter of the cities workforce. The Baldwin Locomotive Company alone employed more than 10,000--the point here being that there were a lot of things that needed holes-

Because it was a manufacturing center, it was also a center for trade unions and associations, and then, much more than today, these groups were neighborhood based, and central to the workers social life, which (being Pennsylvania) meant that they had a need for Polkas.

I could go on indefinitely, and talk about all the musical traditions that were preserved by the various ethnic groups that settled in the various neighborhoods, and I could go into a discourse on the volunteer fire clubs, how they evolved into Mummer's Clubs, and that musical tradition, (which probably ties in here), but I have probably said too much already.
Hazard of the trade;-)