As a result of Sukram's descriptive post 03/03/13 on this subject I decided that during my major restoration project I ought to check out the steering column as the bottom bearing has been "sloppy" for sometime.
I must admit that during this rebuild I have been unimpressed by the quality of some of the parts used by the Factory in 79 and the ball races used in the steering column are no exception - unsealed pressed steel cases, loose ball bearings and a castellated plastic nut at the bottom of the shaft.
Limited lubrication means after 35 years the entire kit is in a very poor state. Hopefully the later cars have an improved system but if not and the end of the steering column has some "play" in it you would be well advised to overhaul the entire piece of kit.
The JW overhaul pack looks like a good option but I feel if one has machining facilities Sukram's plan is superior and will last indefinitely. Ideally one would fit a ball race top and bottom but I doubt the column tube assembly is straight enough to gain a good alignment, so a self aligning bearing at the base is essential.
On the subject of poor components - MAZAC (Monkey Metal) for fuel caps, sidelights, windscreen wiper trims and plastic rear light nacelles, mild steel fixings - ugh! I hope current cars are better.
Despite moans I still regard the old 8 as one of the best.
Finally , if I can offer any help, tips or pics from my ongoing rebuild experiences please ask.