Going Around The Bend!!

My transmission was shot - the third and fourth gear had been cooked and the colour of the oil was that of black treacle.
I dismantled the box and replaced all clutches etc but did not remove the front diff. and torque converter. I also replaced solenoids 1, 2, 3 and A.

1. My first mistake was that I overfilled the gearbox.
2 Early trials with a cold transmission would give good gear changes in 1,2 and 3 with 4 being a bit??.When hot and with too much oil then things went crazy as you would expect!!
3. I removed all the oil and replaced to the correct level. Since then the trials have been somewhat erratic - ie gears 1,2 and 3 changing OK when cold but slipping when hot and 4th difficult to achieve at all.
4. I adjusted the brake band + and -- the effects ranging from noise to serious slip in all gears including reverse ( I think!!)
5. The POWER light does not come on when the car is pushed.
6. The POWER light on startup has given the codes 25 (Engine torque control signal ) and 31 (TPS)- but not always.
7. I have checked the TPS on a digital meter and it would appear to be giving correct values. I have cleaned it.
8. At present when hot it is taking ages to go into drive, is slipping in every gear and there is a "creaking" noise.

My thoughts are - has the servo piston got damaged oil seals?
- is there a problem with the lock-up clutch?
- an oil cooling problem??
- OR WHATEVER?????

The car is a late '93 model with 60,000miles.

Any ideas very gratefully received.

Many thanks
Ron