OK, I will try the 9 o-clock and 3 o-clock positions and
disconnect the cable. It has been removed before, but
always by the dealer (since I got it 2 years ago).
I will need more time to do the cable removal so I'll
probably try again at the weekend.
Thanks for the help.
1957 W121 190
1966 W108 250S
1967 W108 250S (parts)
1982 W123 240D (history)
1989 W124 260E