Strange T Handle Tool What Is It?

[gtarmkr]

I got another strange one I cant figure out. My research says it might be a Piano Tuner? Or maybe a Black Powder gun Bullet Starter? It has a strange handle with a brass tip on one end.  It has a square drive at the end that is about 1/4" wide. No name on it. It measures 4-1/4" wide x 3-1/2" long. What is this thing?

[BruceS]

Piano tuner maybe but the handle is lacking a bit of leverage.    I'm thinking smaller stringed instrument like a small spinet piano or harp.

[john k]

Mortician tool for locking the casket lid for the last time?  I know sometimes they had a small brace type tool for that. 

[william_b_noble]

I'd vote for a tuning hammer for a piano - the brass end might have held a tuft of felt. 

[Billman49]

I also go for piano tuning hammer...

[wvtools]

There is a similar hammer/wrench shown on page 5 of the approx.  1900 Hammacher  Schlemmer Co. catalogue no. 142, Piano, Organ, and Violin Tools.  It has a brass ferrule on one end of the handle with a felt pad.