So here is an update for anyone who’s interested.
I flushed 20 litres of oil through the box and it still never actually ran clear.....although way way cleaner.
I test drove the car and unfortunately no improvement noticed, still revs surging in each gear and a squealing type of noise to accompany the fluctuations.
Today I warmed the car up for around 10 minutes and removed the fill plug, something like a litre of oil spilled out....so was overfilled by myself. (I did originally fill it with the car cold).....then I removed another litre from the drain plug.....the oil was perfectly clean. 2 Dr trannys added and then topped the level up while the engine was running.
The improvement in the test drive was remarkable. Although I am still getting a small squeal and slightly erratic gear change from 4th to 5th, all another gear changes are smooth, with no surging or noises.
I had a feeling that the tc was toast, but I reckon it’s 90% better now....and very drivable. I think I;l keep it and sell my manual one.
Thanks for everyone’s input.