Well thought I'd dig this up to find out how MMZ went with either the E55 mounts (still in?) or gen 2 poly mounts?
Any luck MMZ?

PS - he's a snapshot of the mounts you posted as having received from Steve - suspected to be E55's and below it is a snapshot from AutohausAZ's current cattledog

As per others comments - if no better info on successful alternatives, the cable tie down may be the best.