https://www.woolies-trim.co.uk/category/337/seals
Woolies classic car trim may have the items you want: ~ they do window channel plus inner & outer window scrapers.
These items are used extensively on classic cars so it may be worthwhile looking at other companies doing the same etc.
If you have to use screws for window channel then the heads must go below the glass line.
Polyurethane adhesive & sealant is also very useful for some of the above- messy but will clean off with white spirit.
Hope it helps
Bob.