In a message dated 1/1/2015 1:53:26 A.M. Eastern Standard Time,
msouth@GMAIL.COM writes:

I got  curious about this after someone mailed me off list suggesting it.
You are  right about there being a difference in sizes that breaks at the 85
year,  but from my reading of this that is for the passenger side.   The
driver's side has the same seal size all years, if I read this  busdepot
listing correctly:

the '85-'91 sliding door window is smaller than the 80-'84 one..

anyway the '77-'79 bus also came with sliding windows similar to the
vanagon. theyre obviously smaller than the vanagon ones.
heres a pic:
http://www.rossvw.com/vw/bus14.jpg