About to buy '94 E500

Well, I'm about to join a select group -- the owners of E500/500Es. Within the week I'll acquire a "silver" over "silver," one owner, impecably maintained '94 E500 with 75K miles, driven solely in Southern California. (The seller is replacing it with a '00 E55.) My main concern is staying ahead of the maintenance curve. What preventative measures are most important? What are some major concerns for this type/age of car? Any tips on choosing a mechanic? What price do you think is fair for a car like this? Thanks in advance for your help. I look forward to hearing from this knowledgable group.