David said the rubber seal to his pop-top was in good condition, but was 
getting loose.  I solved a similar problem with my '66 Westy with a 
little form-a-gasket sealant.  I put it on the rubber seal and then 
closed the pop-top overnight.  It has been holding through 6 weeks of 
regular use, with no leaks.

Nick McRee
'66 Westy  '73 Thing

P.S.  I just returned from an 8k summer trip, and will share some 
"observations" and suggestions on parts and maintenance in short order.