Thanks for the replies, i believe i have found the maker.
they giveaway was that verners typically had the locking knob at the 2 o'clock position, mine is at 4 o'clock. A bit of googling brought up very similar Francis Barker compasses from the same period.
You were right about the mark Ipcress, it is either 91 or 16, perhaps indicating a date of 1916?