Yesterday tried the Billion 8800NL r2 test modem/router (complete with RPi ZW running DSLStats) directly connected to the line with all associated POTS extension wiring disconnected, attached the recorded QLN & HLog snapshots.
To my very much untrained eye, there is not really a big difference from the original QLN & HLog snapshots as posted in reply #8 of this thread taken with all original house wiring still intact, perhaps a better informed forum patron could offer a more educated opinion ?
The DS synch speed attained with the test setup was exactly the same as previous with original house wiring, did try 2 additional re-synch's allowing 30 mins. down time between each.
From the tests carried out, have come to the conclusion that any further effort on my part to tidy up the house wiring and fit a new filtered master socket will not produce any worthwhile improvement in DS synch/data speed, neighbours are reluctant to get TalkTalk involved and think that this would be a waste of time anyway.
There likely first response would be, reading from their script as usual, plug router directly into master socket with SSFP removed which of course they can't do as still have old, unfiltered master socket !