The rifle likely was used, no way of telling where/who/when then went through the FTR, then into storage. It wasn't ungraded with Mk. II features at the time of its FTR. There is no way to tell what happened to it after the rebuild. It may have been in storage in the UK until it was sold as surplus and sporterized, or it could have been shipped to any one of a number of countries where it saw service, and was subsequently disposed of there.