Steering notch clarification

Took the rangie for its mot and on the way home the steering started to get notchy. Obviously the first thing I checked was steering fluid and a dribble in the reservoir got that to the correct level. I wd40'd the steering uj's. I have done countless searches online and it confirmed my thoughts about the steering UJ's but most people it was solved with wd40. The only way to explain the steering is as if its very square, which makes me think steering uj again but the fault improves with revs but is still present with the engine off a the vehicle jacked up. Would a new set of UJ's solve this or is it possible it's a box issue? There is a leak from the box but I thought that was just part of owning a range rover and I have been through water which makes me think the bearings might have dried up.

I don't mind spending the money on her but i don't want to start shooting at the hip when ordering parts. The next step will be to remove the Coloum and soak it but I didn't know if anyone had further advise?

Many thanks

Range rover 1985

Apologys if the post doesn't make too much sense, using my phone as I am waiting around for half hour and thought I would use my time wisely

ypu could remove the UJ shaft from the box and posibly vehicle to check properly
also while off drop off the drag link from the arm so there is nothing attacxhed to the box , then move it buy hand