Help identify this round shank single box end wrench please

[rust in the eye]

No makers marks or forged in numbers.
Shank is stamped B-3752 1/2 ( one over the two) , it is 12 pt. and 7 1/2" overall length

 

[3baygarage]

Could be something Blue-Point or Snap-On. Snap-On brake wrenches had a B-prefix.

 

[Millerfish]

I have the same question...

 

[Death Row Dave]

Had a few of them supplied with large Clark process air compressors . Also came with a cheater that slid over the handle . It really was t designed to increase torque but wrench length . These compressors were huge . 1750 HP electric drive motors for power . Our wrenches were not plated but black in color

 

[rust in the eye]

After a bit more internet sniffing I've seen similar tools in other brands being offered as brake wrenches so that seems to be the case.
The maker remains a mystery. Snap-On has been suggested. Did S.O. ever sell unbranded tools?