you could replace the rewireable fuses supplying the ringmain with fuse style RCBO's to ensure RCD protection in compliance with the 17th, so make sure you have a clear earth to neutral before doing anything, otherwise you could be setting yourself up for a right fker of a job
and dont forget to test the ring before you do any work on it what so ever, ie. check for a continuous ring, spurs, inter-connections. if it's not up to scratch before you start, dont start
any problems later on when doing the minor works cert and you will be responsible for the whole circuit
anyone feel free to correct me or add anything, it's late so much may have slipped through the net here...