Yeah, I'd say that's it. I have never heard of such a thing. Looks like an early multi-tool. Pretty cool piece of history.Think it’s called a brace wrench. Been a few posted here, will find a link in a few. Think Lowentraut holds (used) the patent. Yup. P Lowentraut Mfg. Samuel J Johnson patentee.
US Patent: 674,735 - Combination tool (brace wrench)
US patent 674,735 Combination tool (brace wrench) was issued to Samuel J. Johnston of Leesburg, VA. It was granted on 05/21/1901. The 20TH CENTURY / PAT. MAY 21, 1901 brace wrench has . "P. LOWENTRAUT MFG.CO. NEWARK N.J. and "TERRITORIES FOR SALE BY S.J.JOHNSTON, LEESBURG,VA". stdatamp.org
I have several variations of those in good condition, but would be happy to buy another. That one is called "The Prince".