ASM 2002 90 Transit

[PandAMK6]

Hi everyone, I am not 100% sure on this but I think my ASM van may need a new clutch.

The symptoms are

Not changing gear all the time even when at high revs especially when going up slight inclines
Not changing gear smoothly
Occasionally a good thud and seeming to engage the ABS

Does that sound?

Any help would be great as Ford have quoted me £800 for a new clutch fitted with reprogramming but I don't want it to open a can of worms that I don't want to pay for lol.