31 Cabriolet Rear View Mirror Arm

[Ed in Maine]

My cabriolet uses a late arm casting for the mirror. I would like to get the arm chrome plated but I am finding that the clamp for the mirror is held captive by the adjustment ball. It looks like the ball is welded to the arm. What is recommended to get the arm replated? Ed

 

[jw hash]

they are peened on the end of shaft going through the arms, I take them apart have them plated and JB weld them back together. Oldblueoval has the arms cast.
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