Founded in 1900 by a Mr. S.Wolf, in 1913, his company became properly established by registering S.Wolf & Co. Ltd. - this being changed in 1949 to Wolf Electric Tools Ltd. Products and agencies included, over many decades UH magnetos, spark plugs, Solex carburetters, engine reconditioning equipment, a wide range of domestic and industrial electric drills, garage equipment, valve grinders, double-ended bench and pedestal grinders and polishers, die grinders, flexible shaft grinders, electric screwdrivers and hammers, valve-seat grinders, a combined mortiser and drill unit, filing machines to trim distributor points, portable belt sanders, saws and groovers, soldering irons and guns, a lathe toolpost grinder and numerous attachments for the amateur-market drills including lawn edge and hedge trimmers, drill stands, table saws, jig saws and a simple wood lathe.
In 1935 a new factory was opened - the Pioneer Works in Hanger Lane, London W5 - a fully-equipped enterprise with a design and development department, centre and multi-spindle automatic lathes, milling machines, coil winders and gear cutters. By the early 1950s they were claiming to be Britain's largest manufacturers of electrically-power tools - a No.2 works having being opened at Brumwill Road, London W5 - and in 1961 the workforce reached what must have been its zenith at some 1200 - this falling to around 850 by 1978. Taken over in the 1980s by Kango Tools Ltd. of Peterborough, the Wolf name was dropped as the new owners rationalised the model range. Although many of Wolf's domestic market drills (many listed as the "Cub") were not of great power or longevity, all their industrial products were, especially the "Sapphire range", and it may habe been one of these, a huge unit with a No. 2 Morse taper socket that nearly pulled me off my feet one day when the drill bit jammed….
So, what's a Wolf valve grinder doing in the machine Tool Archive you might ask? Well, I admit it's a trip down memory lane for, many decades ago, on most Friday nights - and often into the early hours of a Saturday morning -  your correspondent would prepare his daily-use 1930 Austin 7 for a spot of economical motor sport on the following days. Grinding in the poor quality valves always improved performance, as did the occasional reface on our Wolf grinder - this, on one occasion, helping us out of last-minute trouble by regrinding the end of the steams on a set of new but over-long valves. Happily, the grinder must have been a Type SR454 (I'd no idea what it was at the time), for not only could it regrind valve faces and ends as on the cheaper models such as the VR5, but also tappets and (with an attachment) rocker arms. It had a proper compound slide rest, built-in, filtered cooling (with a magnetic trap) and a diamond wheel dresser. A light unit was part of the standard equipment and, thoughtfully, dowel pins were provided to restore the two slides back to their standard settings of 0°, 15°, 30° and 45° - a degree scale being provided for the intermediate positions.
All Wolf valve grinders were well made - as was all the Company's  professional garage equipment - and it's not unusual to see models made in the 1930s still working perfectly. My own Wolf double-ended bench grinder, manufactured in 1950, is in constant use has only needed one new capacitor (and a few wheels, of course).
However, as quality costs, the SR54 was not a cheap machine: in 1954 when the model was introduced, working men earned an average of £9 a week while today, in 2017 it's £505. Extrapolating those figure would update the £147 : 10s : 0d cost of the Wolf to an astonishing £2409. However, in 1954 it was possible to buy a new (if modest) house for an average of just £2000 - but today's corrected figure for that amount, based on inflation would, be just £32,600, barely enough to cover a deposit..