Thanks 2x95... I went ahead and reassembled everything seeing that I wasn't going to get the old mount out. (or the new one back in!

) I managed to get all the bolts out, but as you advised, there's no way to remove the mount. I did manage to stuff a slab of rubber on the underside of the rear roll restictor and fill it with polyurethane using a hose attached to my caulk gun.

This will have to last until I can get it into a shop to do the work. The polyurethane should be dry by about midnight or so...