While it would be nice to know if Steele Rubber is referring to the curing of the rubber itself or to the bonding of a joint in the rubber (or, to both), the important issue with respect to the original question is: is the Steele part one, continuous piece - their description (and their use of the word "vulcanized") does not suffice as an answer to that question.
When I bought my 1954 Suburban in 1971, it had what I assumed were the original rear-glass pieces, and they were not continuous pieces of rubber. However, I would prefer a continuous piece of rubber (whether or not it is "correct") and I would trust Steele to make a seal that would last quite well.
Maybe someone will call Steele and get a confirmation about their part being one, continuous piece. Sorry, Bill, I assume nothing, especially at the risk of the cost of a Steele product.
