COUV, that is a good explanation at a DIY project, Thanks for the write-up. I can't imagine trying to use the swivels on the 3/8" I know you found religion in that effort. I believe using a ratcheting box wrench ( see picture) would make the job easier and I'm guessing removing the exhaust pipe would give you more working room. I would suggest anyone else trying this exercise watch the clearance at the firewall when lifting the engine so as not to damage anything at the rear of the engine.
I changed the engine mounts on a M113 engine, CLK 500 using a very similar method to your's. GOOD JOB!