Well, I'll continue this discussion by myself. I had the car up on jacks. The jacks support the car via some extension pipes I made. The pipes are 3/4" thick walled metal tubes approximately 8" long and bent in the middle on a press to an angle of about 10 degrees. These pipes slide into the four jack holes in the rocker panels and the portion which extends out from the car nestles into the saddle of the jack.
Since my last post I did replace the motor mounts. On the W124 with the inline sis engine, the easiest way to swap them is, with the car jacked up as described, loosen both 8mm allen bolts from the under sides of the mounts and completely remove the one on the passenger side. Then remove the 17mm hex bolt from on top of the passenger side motor mount. Lift the engine with a jack under the oil pan. I used a 12" x 12" x 2" oak plank to help spread the weight out over the oil pan. The car should be lifted just enough to slide the old mount out. There are no other bolts to remove.
Lift the engine any additional amount required to slide the new mount in. Loosely screw in the 17mm top hex bolt and the 8mm bottom allen bolt.
Completely remove the driver's side 8mm allen bolt. Lift the engine as far as you dare. While standing on the driver's side of the car, reach under the aluminum air delivery stuff that fills the top of the engine bay on the driver's side. The higher the engine is, the easier this is to do. Using a 17mm box wrench, loosen the top bolt. I basically pried my wrists against the aluminum air whatchamacallit to break the bolt loose. Once I had moved it an 1/8th turn, it came out very easily. Remove the bolt. Remove the old mount. screw the top bolt snugly into the new mount. Drop the engine until this new mount is just above the frame. Screw in the bottom bolt. Tighten the driver's side top bolt as best you can. It's more difficult because the engine is lower. Drop the engine and tighten the other three bolts. You're done.
One other comment; I had already removed the radiator, hoses, fan shroud, and water pump for other reasons. I don't know if any thing would need to be disconnected in order to replace the mounts if this had not already been done. I still want your help on the other issues.