One thing I often see that destroys motor mounts prematurely is the lack of properly tightening the stud nuts that clamp the motor mount bracket. If these nuts are allowed to become loose the motor mount bracket or bell housing ears will vibrate over the threads and wear them away to nothing. All three of the mounts on this Ericson 34 had badly worn threads.
Worn threads will prevent any future re-alignment and require new mounts whether the rubber is ready to be replaced or not. One of the mounts was still in operable condition had the threads not been destroyed by letting the nuts come loose. The other two were toast and both spinning in the rubber.
In order to replace these mounts with a different model or brand would have entailed a far more costly and time consuming job due to differing bolt centers for the mounts. The three point design of the Ericson motor configuration is likely dependent on the rather stiff lateral design of these mounts. It was decided, though not happily, to re-place these mounts with the same brand & model.