I don't know if this will help you but you could try, Andy Gayle, Smethwick, 0121 558 4848. I've never heard bad reports. Also, but maybe a bit too away is, Andy at AutoBarn, Ledsham, 0151 347 9999/07914 805586. I believe he's popular with the W201 boys.
Please note, I've no experience of either.