The curse of the "O" strikes again...
There has been a LOT of mis-information over the years with the name "Overlander" and the "O" in VIN/Serial numbers. There is a very old document still floating around the internet that states the "0" or "O" stands for Overlander which was a 26' Airstream (available in both the Land Yacht & International versions). It is wrong and keeps being perpetuated as it is impossible to purge it from the internet. The "O" does NOT stand for Overlander. Overlander was the name for a 26' trailer - not a VIN# descriptor
California made -
"0" (zero) or "O" (Oh) = Land Yacht package
"I" (eye) or "1" (one) = International package
The International package had a few extra bells & whistles. The way the VIN# should be interpreted is:
0 or O = Land Yacht package (I or 1) = International package
4 = 1964
2 = double bed (1) = single beds
S = Santa Fe Springs, CA (J) = Jackson Center, OH
5## = 3-digit number which is the sequential build number of the trailer
The organization of these numbers/letters vary slightly in the 60's & 70's, but they pretty much remain the same. And "O" never means Overlander.
Check out this webpage
for more info & pics on various lengths of trailers and VIN # interpretations.
Hope this helps.