Eric, the old firm of William Horton has recently re-opened as W. Horton & Sons, 45-46 Loveday Street in Birmingham.
"Oliver [son of William] had two daughters and sadly, in the 1920s it was not the done thing to pass on a Gun Making company to a daughter! The stock was sold to Arthur Allen in Glasgow in 1924 and the records were passed to Olivers cousin James William Horton (who worked for BSA), the great Grandfather to Steve Horton (the current custodian and owner of W Horton & Sons)".
http://www.hortonguns.com/They might be able to answer your questions.
