Ohil,
Sounds like your heat gun was the same vintage as my iron. I was tightening up the ChinaKote on a Tutor II last week and it started to fele weird when I pressed down. I use an old cotton sock wrapped around it and tied over the handle- so I couldn't see what was going on.
Well the handle is attached with 1/2 dozen spot welds, and they all finally let go, next thing I know the shoe is hanging from the wires! Cheapskate that I am - I spent 2 hrs taking it apart and drilling / pop riveting it back together.
Looked at the box and realized I bought it back in '88, so I will see if it lasts another 20 yrs.