So I took delivery of a brand new 1312 italk branded router. It wouldn't accept the standard admin password despite the italk documentation saying it was that. I did a factory reset and bang we're in with default password.
Interesting to note it was on V6 of the firmware so upgraded that to V12 and loaded a backup configuration from disk. Interesting to note that the backup configuration must contain the supervisor password as I can now log in with my password from my other router on V12 after loading the config file.
Only tested for 10 minutes but seems to sync a little slower at 68½ down whereas the other older one syncs at 71½ and after I swapped them back the old one showed the same sync. Must admit not extensive testing of the new spare one could have been a bad retrain but it is a spare in case the old one goes pop.