Without any other clues it's almost impossible to come up with anything but a basic educated guess. E41324 is most likely a 1917 BSA or a WWII era Lithgow or Ishapore. SSA is a remote possiblity, but LSA didn't use an 'E' prefix on MkIIIs or III*s. I don't believe EFD used 5 digit numbers, but I may be off base there.
A 4 digit, no prefix number has too big a range of possibilities to even hazard a guess.
Any other marks anywhere on them?