Was the new UJ a tight fit? Should be.
Also, most UJ's need oversize circlips, and these are available from the specialists. Can be fitted in situ. Support the back end, remove a circlip and carefully knock the UJ cup in. Fit the oversize circlip. Rotate 90 degrees and repeat. You may get 4 oversize clips in, you may get one.
Regards the prop, how are the UJs in that?
Recently had a chap pop round with his herald, terrible vibration at about 50mph. Really bad.
I had heard that removing the straps and bolting it back together solid can sometimes work (even though itputs the UJ's out ofphase)
Anyway, the car then drove perfectly. One happy Herald owner. Saved buying a new prop. And took 5 mins.