Another little update for those who are still following this...

I finished the jig. Once done I see that there is not quite enough material removed from the center 'post' of the mount.



I will probably be hogging off some with the mill once I get the piece secured in the rotary table. If I can secure the base I will be removing more from the inner wall as near to the outer metal sleeve as I can.

Some of the articles have suggested burning off the rubber, but this is ecologically unsound.

There are factory rivets in the mounts that were used to fill them with fluid. I will probably just drill them out and tape them over before pouring the polyurethane.