I bought this little 4 1/4" Acme style on Ebay. It was described as a Whitman & Barnes, but to my surprise, it is not W&B!
W&B bought the Acme line of wrenches from Capitol Mfg Co. in 1893. W&B's familiar logo was patterned after Capitol's, thus the confusion. On this wrench the upper portion of the mark is very thin, but I can make out a "P" on one end and a "B" on the other. This matches Capitol's mark of "PAT" and "FEB".
The rest of the mark is 27 and 83, denoting Feb. 27, 1883, with HERCULES in the diamond.
W&B's Hercules has the adjuster on the upper bar rather than on the lower like Capitol.
I have a wrench from before 1893 in my hands!