giving the car a face lift

[Robo]

Mate read whole thread and I have to say GOOD ONE BUD.
Awesome job.
Your air brush mate, we all wish had a friend like him.
Now the panel you mention above gutter is the roof panel -Turret.
it overlaps the assembly and is the last of 3 pieces here.
roof or turret on top side-door frame panel, and gutter underneath.
These 3 are fixed together at different stages of assembly of car.
roof is fixed to side panel and gutter fixed to these last underneath.
body sealer is the product you see in the gutter.
this seals water from getting between the panels.
and you'll notice this sealer on the underside above windows to seal this side of joint also.
Here's where at least 2 problems start.

Number 1 killer of this seal is the roof rack.
It will break this seal, and water gets in, end of story.
2. The seal is flexible and with time dries out loses it's flex and Cracks/splits.
Again water gets in.

This is a big job to describe here, ( for everyone ) I'll start a thread titled" roof gutter maintance".
My brother inlaw's a panel beater and shop foreman, walked me threw this repair.
and I did it myself over chrissy to wife's lwb gq.
hopefully "before" you mate paints whole car.
I'll take a pic of repair it's not perfect, but that means you can understand better what I'll be getting at.
It's not perfect because I'm not a panel beater spray painter.
Previous owner sprayed car and hadn't cleaned gutters properly, paint started lifting in the gutter "away from joint edge thank christ".
Hence the repair.
Again, good luck with restoration,
Cheers.