My catalogue doesn't have a page 278, stops on page 277, but I've got
the 2002 edition. However I;ve got the Rover Group, Metro joints on
page 204 where you will see that the alternative to 23039 (metro
1981-1990) is the 23931 (Metro 1989-1998) I believe that the latter
joint is the waterproof one and that's the one we use. The Mini joints
on the adjoining page are apparantly identical but definitely not
waterproof. All these joints need de-preloading but last indefinitely
as long as the boot doesn't leak the grease out. You can fit a grease
nipple to the steel cap, use a waterproof grease..

The 23880 (34mm x 1.50mm R/hand thread male) joint is the bottom ball joint we use in the 'lower, outer'
wishbone position in the centre of the hub. That 23885 looks
interesting, small, haven't actually looked at that in the metal.

The BMW roll bar joints that might be even better (with a little
threading on the rod maybe) are on page 32 in my book for BMW, 7 serie
E32 and 8serie E31 listed as 21383 with an 'E' suffix for the
low-stiction version.