CF and LK
Apart from confirming that which TimG posted, i.e. CF means Charge-Full (not that Tim's comments need confirmation), I have checked my monograms and "LK" is the Kelly Engineering Co.Pty. Ltd. of Redfern, New South Wales. This would fit with the original manufacturer and the Primer filler.
Interestingly, the same list shows "MC" to be the Ammunition Factory, Finsbury, South Australia. Was this a different name for the same place, perhaps when taken over by the government?
On the other case, "ECC" is E.Curran & Co. Cardiff.
Regards
TonyE