r129 shimmy and vibration gremlins. Point me in the right direction
 

1992 500Sl, 114k miles.

New: Michelin Pilot Sport A/S plus, 225/55/16 on OEM wheels. Balanced twice, road-force balanced once.

recent: new shocks/struts, new control arms, new tie rod ends, new steering shock, new wheel bearings, new pads and rotors.

Steering wheel shakes and shimmies in a pronounced way above 45mph. Rear view mirror shakes. Issue began after new wheels and tires. Tires have road-force balanced out to .10 on the computer. Tolerance is supposedly .75.

Ideas?

If no other work was done when the tires / wheels were changed, it pretty much has to be a tire / wheel issue.

Lift the front of the car and spin the wheels and look for wobble. If the wheel hub bore is corroded, the wheels may wobble if the hub face does not make full contact with the wheel.

Do you have any other wheels / tires to put on the front? If not, move rear to front and try again.

Past that, I'd say a drive shaft joint is coming apart.

Wow, that's interesting. The wheels I put on were only used for one set of tires, and sat in storage for over a decade. They didn't look any more corroded inside than any other used wheel, but who knows. Driving it again today, it doesn't seem like a perfectly rhythmic vibration, rather an irregular wobble, sort of like you described. What can be done if it's the wheel? How can you tell, via naked eye, if that's the issue? Would it be blatantly obvious? Nothing seems driveline-related as it's all dependent upon speed, not RPM or acceleration

You will be able to tell by eye when spinning the wheel. I've run wheels / tires that wobbled 1/8" laterally on a cars less isolated than an SL with no ill affects so you will be looking for something drastic. A square block can be balanced but it won't roll so well.

You can still have a driveline imbalance. Remember, the drive shaft spins about 3x wheel speed. If you are in direct drive ( top gear not overdrive. ) the drive shaft spins engine speed, if overdrive some % over engine speed.

are the front wheel bearings set correctly? - they are usually on the tight side when compared with any other car with similar setup.