I beg to differ.
I have four post war Fazakerley manufactured No4's in my collection. All have inscribed/electropencil serial numbers and bolt numbers. Two of them came direct from military storage in original factory wrappings and in original cosmolene. They are 100 % genuine as is, in my opinion, the rifle offered by this seller.
FWIW : I have never seen a stamped serial number on a post 1946 Fazakerley rifle. All are scribed on, rather crudely I might add.