Amish,
I think your application of the metal tabs from a VW, is a good solution for the broken plastic tabs.
I like that they clamp on and can be re-positioned on the glass.
I also like that they allow for some flex or change in the angle of the glass to the angle of the lifting arm.
Something the plastic can do but the SBC metal brackets cannot.
As noted in the links, this is only one of the problems with the power windows.
I still use the plastic tabs and my windows still work great,
after the careful adjustments to the regulator track, that I have written about.