Never saw one like this at the flea market or on ebay.
http://www.ebay.com/itm/Antique-Adjustable-Wrench-Double-Headed-1800s-unusual-bicycle-motor-cycle-/290643717312?pt=LH_DefaultDomain_0&hash=item43abb72cc0
Not to sure about the description but I figured it was intresting.
Baxters patent S wrench, tho it should be marked, odd that it isn't.
The sellrs description tells me he doesn't have a clue what it is, tho, somehow, his wild date guess isn't far off....
there are others around in better shape bob w.