After about 3 years of searching I finally found another 400E. This one is by far the most rust free W124 I've ever had however it did have some running issues when I got it. Car was going into limp mode as soon as it was warmed up.

The seller told me his "mechanic" told him the "Cadillac Converter" was bad but I suspected it was something with either the harness or throttle body. After getting the car home and reading the codes I found one of the 10A fuses in the BM/GM module was blown. After changing the fuses and clearing the codes I now have a very nicely running 400E.

The car was sitting for a few years so I've had to do a bit of deferred maintenance including new plugs, wires, distributor caps, rotors and insulators. I also put the 17" Monoblocks from my old 300TE on the car. Future plans include a full suspension rebuild and lowering with H&R springs. Ive had two prior W124's with that setup and have loved how it handles.