Thanks again! The 300SD has all the improvements as listed above by Machnumber2. I don't get reimbursed for expenses. I can however, write miles off on my taxes.
I think it's down to the '85 300SD or the '86 420SEL. The refinements of the 420 are tempting because of the long hours between stops travelling Texas. It's not unusual to go 3-4 hours between stops. The smoother quieter ride is a big plus.
The 420 looks and runs like new. The 300SD is pretty nice, there are a couple of dings in the body and the paint is pretty good. I'll sleep on it.
91 300E 120K
90 300SE 275K (sold)
92 BMW 525iM 120K
90 BMW 525iA 175K
85 300D 175K (sold)
84 300SD 245K (sold)