Covered tang blade too worn to read name

It could be YSC Ltd. They were originally called the Yorkshire Steel Company Ltd, but after some time changed the name to The YSC Ltd. They were certainly producing razors in the early 1900s (can't find the date of incorporation, so maybe even earlier) but changed to safety razors and blades. A 1910 article invites readers to write for the Y.S.C. booklet c/o The Yorkshire Steel Company with a registered address at 30 Holborn, London, so the change of names was on the books then. In 1911 they were producing the YSC safety-razor kit. An ad in a New Zealand newspaper in 1915 still uses the original name and YSC as a brand of razor blade (along with YOC) and an article inside the paper says that they used the 'finest razor steel in the world' and that it was an 'all British company making all British goods.' In WW1 they made a 'holt flare' - attached to the underside of planes (US planes are cited in the document) to light the landing area at night. At an Aircraft Industry convention in 1920 the company had a table displaying safety parachutes, landing lights, flares, air depth-bombs and anti-friction metal for aero-engines. The address, once again, was given as 30 Holborn, London, EC. An Air Ministry Specification of 1933 quotes Y.S.C. specifications, and also quotes the Yorkshire Steel Company in connection with Air Force flares. Another newspaper ad from 1952 refers to the Y.S.C. which incorporated the 'business formerly known as the Yorkshire Steel Company, Contractors to British and Foreign Governments' - the ad was for flares, signal rockets, very pistols and cartridges. So it seems they went from razors to safety razors to the aero-industry.

Regards,
Neil