1999 Peterbilt roof replacement

1999 short hood day cab 379 Peterbilt

I’m replacing the roof and am not 100% sure what to put in between the cab and the fiberglass roof. The stuff I removed from the joint looks an awful lot like the stuff used around windows. To my knowledge it is the original roof after 17 years of other same owner history (can’t speak from before that).
What do you suggest or what are the groups thoughts

 

Just for further information and I’m asking.
This is what I was suggested from the local Autobody shop. I know it’s not paintable but sure makes a good seal for glass. Thoughts?

DINITROL 9100 HD

 

I do have a second question for attaching the new inner fender liners on my brand new aluminum front fenders. Scrapped my old ones because the rocks have all but destroyed them.
What is the preferred attachment method? Some type of epoxy or a 3M double sided tape seems subpar

 

I didn’t count how many I drilled out, but boy howdy is there a bunch.

 

There was no huck rivets holding the original fender liners in, I’d like to keep holes to a minimum on them

 

Door has been installed.

 

Progress has been made, color and clear, chrome going back on now