I received my order of OEM engine and transmission mounts from eEuroparts yesterday. Weather was in the 40s so with some step-by-step guidance from Chuffsy, I replaced B230FD mounts for the first time.

I did the front (which was much less troublesome than the guidance and comments initially suggested)and moved on to the transmission mount. Unfortunately, one of the captive nuts in the cross-member gave out and I had to abandon replacement of the rear mount. The rubber's in good shape, so I won't worry about it unless it becomes a problem.

So, with the new front mounts the engine still has a subtle vibration, but the shaking (and knocking) seems to have stopped. I think that the old worn mounts were definitely part of the problem. I'll give it a couple days and report back on the situation.

Thanks for the pointer to the engine mounts!