Antique Frank Mossberg Co. Attleboro Mass.USA  Alderman 6 inch adjustable wrench/ spanner . Great vintage collectable , primarily made for use on bikes , shaped end ro handle for tyre removal. 
Patented November 13 1900 , Mar 11 1902.
Very rare find in the UK market, wonderful addition for vintage tool collector.
Please see all pictures for condition and details.