It's @4-1/4" long. I thumbed through both Cope 1830-1915, and Schulz's, and couldn't find it.
Looks like a mark on the body. Can't make it out at all?
I looped it and couldn't make out anything.
Could be a GEM by Tower & Lyon, but I don't see one like it in the pictures of GEM and T&L that I see.
I though it may be made by Whitman & Barnes or Speirs & Co.
Peck, Stow & Wilcox made a similar design called the STAR Bicycle Wrench in 1897 (see pg. 11, June 1995 MVWC Newsletter for a copy from IRON AGE) , but it was an open "skeleton" handle all the way, not closed in between the fixed jaw & adjusting nut. Are there any marks on the shank of the movable jaw?
Nothing on the shank either. Here's an open pic.