This year we replaced the Spreader Arm Mounts on the Christopher-Jin.
Catalina Direct recommends that all the old style pot metal mounts be replaced. They can fail without warning.
Shown at left is the newly installed Stainless Steel Replacement Mounts.
The trickiest part of the process is getting the compression tube fourteen feet up the inside of the mast and aligned so you can put one of the two through bolts on. We used 3 five foot lengths of pvc water pipe with the compression tube taped to the end. What complicates the operation is all the wires, and in our case a mouse nest that was blocking the path about 10 feet up.
We found the other issue was keeping all the sheets and lines untangled and on the correct side of the mast.
Figure on about 4 to 6 hours beginning to end. And you will need two deep-well sockets because the lower through-bolt is inside the cups of the two spreader mounts.