It's not bondo,'glass,or welded.It's a 2-part bonding adhesive(by 3M part#8115 I think)I used to work at a restoration shop,they turned me on to it.Stuff is tough as nails.(it's actually what holds pre C-5 corvette bodies together,and on the newer ones it holds the body to the frame)The handles were still a pita though because they don't actually sit flush,even w/o the gasket,had to grind some off of the back of the handle itself.I did those when the car was still white(5yrs. ago)and have yet to have even the slightest crack in them.Did not want to weld them in case I ever have to replace the handle, this stuff can be removed with high heat(~600 degrees)and some patience.