It's a Lee Enfield but it never was a Metford.
What you have is a Mk.III or No1MkIII in post 1926 nomenclature made as you know by London Small Arms.
LSA is one of the rarer WWI manufacturers to find. From the looks of your rifle the stock has been refinished. Do all visible serial numbers match?(receiver, bolt, forearm and nose cap) You can also check the barrel number by removing the back hand guard.