W123 Application, rear window.

Removed rear window to replace headliner. Got my seal and getting ready to re-install glass.

The GREAT news: ZERO rust ...

The Odd news: looks like plumbers' putty was used around the channel.

Is it safe to remove this stuff? Why was it installed? Did the factory do this? If removed, do I have to re-add new putty?

I want to clean out the channel and apply clear POR-15 so it won't ever rust ... ever ...