Hi Kay thank you for your question. There are a few sponsor's mark with the letters EH, not necessarily British.
As an example, Egor Cheriatov, fine jewelers, Mocow and St. Petersburg ca 1890's 1919 uses the initials EH.
If you cannot attach a photo in a follow-up submission (where I can move to this one) then please provide more information. What shape do the letters E H appear in? A rectangle? Is there a dot between the letters? Are they in script?
