The 39-216 worked perfectly!
A quick learner from East Providence, RI says:
May 18, 2013
Just wanted to thank you for the quick shipment, etc! The arm fit and worked perfectly. This was quite a bit easier than I thought it was going to be when my original arm broke a few days ago.
Tom from SWISCO responded:
May 20, 2013
Great news! If you need anything else, please don't hesitate to ask. I would be more than happy to help in any way that I can.