Robert,
Step One is educating yourself on the W113. This means understanding the VIN number, Engine Number, Option Code Numbers, etc.
Step Two is examining and driving as many of these cars as possible. I recommend you drive every example for sale, regardless of condition, within a 2 or 3 hour drive of your home. When doing this, take every car seriously as you might find a rusty & beat up car with a well tuned engine or some other unexpected combination. Even if the whole car is almost junk and needs an entire restoration to be useful, you could probably end up learning something by closely examining it and driving it. Experience is priceless!
Pagoda World #4 will be mailed out very soon (I'm stuffing envelopes tonight) and it has a very comprehensive summary of things to examine. If you become a full member, you get Pagoda World. They are available seperatly on eBay from time to time.
Best of luck in your hunting!
Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both tops
1994 E420