This is the glazing trim that I purchased to fix up the windows
on my '78 B-15 Beachcomber
This was the closest profile that I could find to what my windows
have currently. Although, I have not tried it out yet and see if it works.
My other suggestion would be to remove the windows and replace the butyl tape that is between the window and the fiberglass. I noticed that my butyl tape was dried up and was most likely a reason for water getting in.