An interesting wrench. The features are not inconsistant with Williams , the forge mark is about right, the head shape is about right, the use of an inset panel is typical of early (<30's) williams.
The overall design however is not like Williams standard production Engineers wrench at all. The standard wrenches have a much thinner handle that grows wider away from the head.
But it could have been a special, Bliss was certainly big enough to order what they liked...
> viable suspect but no confirmation
Probably always going to be a touch of doubt, unless you find a machine manual with a closeup picture of the wrench in it. But, I know E.W.Bliss used 'EWB Co' on machines from pictures. Ruling out all the other possible folks who might have also used that is a chore....