two wrenches i found yesterday,stamped made in england...B.S.F. ?

B.S.F. likely refers to "British Standard Fine" nuts/boltheads.  As I understand it, the British used differently sized nuts/boltheads for fine thread (BSF) than for standard thread (British Standard Whitworth, BSW).  You'll often find "Whitworth" wrenches marked "[X size] BSW/[Y size] BSF," referring to the major diameter of the thread, NOT to the nut dimension.  So the 1/2" BSF max on the range would mean it fits the nut for a 1/2" BSF bolt, although it's pretty short for removing a well-torqued/well-rusted nut that size.

Imagine being a British car/motorcycle mechanic, machinery mechanic, millwright, etc., and having to pick the right wrench for a nut you encountered on a repair.  You'd probably get pretty good at it, just as mechanics/repairfolk working on equipment with inch/fractional and metric parts: look at it, pick the right wrench.  But it might take longer.

ok thanks,not sure about the SLIK ,they are nicely chrome plated

Of course, this also means that you can't use the wrench on SAE or metric or, for that matter, Mesopotamian fasteners 

haaaaaaha

Empire / Empire Mdsg. Co., 140 Marbledale Rd., Tuckahoe, NY / importer of "SLIK" adjustable wrench / see Macdowell Equipment Co. Ltd., Romford, England /

Macdowell / Macdowell Equipment Co. Ltd., Romford, Essex, England / "Slik" adjustable wrench / patent GB 650363 Oct 29 1948 Charles Wilson Macdowell /

that same design was manufactured in Germany by a company that stamped it "SUL":

Schmidt / Fr. Paul Schmidt, 20 Herrenstrasse, Suhl, Thuringia, Germany / "SUL" wrench / patent DE 342600 Oct 20 1921 and patent GB 169675 Dec 1 1921 / https://www.datamp.org/patents/displayPatent.php?number=342600&typeCode=0&country=DE /

There was a U.S. manufacturer as well:

U.S. Wrench / U.S. Wrench Co., Philadelphia, PA / "Bohn Quickfit" wrench / patent 1481250 Jan 22 1924 George J. Bohn and Fred W. Werner /

Interesting design. I have one or two of those here in my bicycle wrench collection.

This wrench is very similar to the Fitzall wrenches.