Where can I find a repair manual in print for an 88 560 SL?

What is the recommended tire size for this vehicle, and who online would have the best prices?

The factory radio has dashes across the front and does not work, the owners manual states that someone attempted to remove the radio, however it has been locked and garaged since Oct. and I am the only one with access to the garage. What could it be?

Any help would be greatly appreciated.
Hank

 

Pull radio and look for the code or ask the dealer, tire size should be on driver door pillar