Well after 30 days of starting this and nearly £150 pounds later, I have now working TU-719 and AU-919. I have forgotten what good sound feels like. Only issue I had was with the black ribbon cable, does not like to be touched too much. Needed to be removed from the i/o board stripped and re-terminated.
Could not do much on the Distortion setting on the MC board, just followed as if no THD meter and as I do not have a MC pickup to worry too-much.
The Oval caps are like mini tardis, they have so much gunk inside.
Started working on the SR-525 turntable, speed control is very erratic when you move the pot on 45rpm, must be a noisy pot as 33rpm control is fine. While I am there I will refresh any elctrolytes.
Worth the money, time and effort. Also, added the Arcam Rlink bluetooth receiver, amazing piece of kit combined with the Amp.
Thanks all for the help and suggestion to make it last another 3 decades.