Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
They are all the same, I've heard reports that they tend to rock when fitted. You could buy the cheapest and fit the cover onto your base.
You could buy the cheapest and fit the cover onto your base.
Some years back I re-trimmed a 550 K1 seat with a repro cover. I carefully cut the chrome trim moulding from the original seat cover, and glued into place over the new cover once fitted to the old base.