Larry Smith wrote:

Well, George, let's put it like this; I don't have the information
firsthand:

Cessna only sends the SB to the person who owns the plane when the SB is issued.
If you're trying to deal with an old service bulletin, you will indeed have to
buy a copy. But Cessna does send one out free.

George Patterson
Great discoveries are not announced with "Eureka!". What's usually said is
"Hummmmm... That's interesting...."