Years ago I had a very seized arm on a pivot of the 1600 (Mk1). Normally, a little oil a little pressure loosens the arm up. This one wasn't having any of it. Well, I thought I would hit the pivot with a heat gun at low heat. I watched the whole arm piece melt in front of my eyes. I don't use heat guns anymore.
Once bitten, twice shy. Thnx for sharing that embarrassing moment and sparing us a costly lesson. I suppose I could make up a nice listing of my own sometime.