In the few miles I was able to drive the car a few weeks ago it was very apparent that the transmission mounts needed attention. Since the engine's out again I went ahead and replaced the rear mounts. Replacing the front mount is an ordeal that I'll try to leave for later.
When I loosened the 27mm rear trans carrier bolts the large 20M spring washers broke in half from stress and age. I tried all my usual local sources for replacements but no one stocked them. Luckily McMaster-Carr came to the rescue. McMaster has pretty much everything you could ever need in the hardware department.
The old mounts were -- in a word -- toast.