Fitted for but not with predates modern procurement

Was fitted for but not with a pre-Second World War naval practice?

Yes. Sloops and Victorian warships carried fittings or provision for equipment, including guns landed for shore parties, without always carrying it in normal service.

The concept predates contemporary cost-saving programmes. Warships could be designed to accept weapons or equipment that were not permanently embarked. Sloops and Victorian ships that landed guns in support of shore parties provide earlier examples. The practice has a longer history than recent criticism of the Royal Navy suggests.