Okay, I finally found out the manufacturer of this weird shower arm configuration --- It's a Symmons NU-Arm #301.
<http://www.symmons.com/Bathroom-Products/Symmons/Symmons-Shower-Arms-and-Head-Brackets-301.aspx>
Looks like it'll need a male-male adapter for a standard shower head to attach...
I have a shower with dual shower heads (each on opposing walls) with the same type of weird plumbing.
This must be a Massachusetts oddity?
The supply pipe sticks out about 3" from the wall with a fitting on the end.
Each pipe is solder in place and in my case they seem to be held firmly in...
