The London Authorities (Transfer of Housing Estates etc.) Order 1973

31.  Any extension of service under section 7(1) of the Local Government Superannuation Act 1937 effective on the relevant date in relation to an officer transferred (or deemed to have been transferred) by article 23 or 24 shall continue to have effect as if it had been made by the authority to whose employment he has been transferred (or is deemed to have been transferred).