Brian B.
I would go to the top and take all of the old sealant off and replace
it with Vulkem 636. If you haven't as yet, check the vents to be sure they are
not in need of the same treatment.
You can get Vulkem sealant from INLANDR.COM or Airstreamdreams.com.
Martin and Rachel Hughey
WBCCI 10212, Vintage A/S
1969 International and 1961 Bambi