To SavageSun Willys:
Here's my interpretation of the chassis/model codes. Your wagon should be a MODEL #54168. That would show on the I.D. plate if there's one still on the wagon. Looking at the chart, the MODEL numbers break down as: 5=1955, 4=Flat Face Cowl (whatever THAT is!), 1=2 Dr. S.W. Body (I-Beam Axle), 6=6 cyl. 226 cu. in. L-Head, 8=All 4WD.
Your SERIAL NUMBER is 13962 which fits in the sequence shown of numbers 5001-16513. 5001 was the first one built and 16513 was the last.
That should make your wagon a 1955 6-226 4WD Utility Wagon when it left the factory.
My 1954 Wagon has a serial number of 654AA210363. That shows it to be a Model 685 Station Wagon Deluxe which came from the factory with a 6 cylinder engine. However, somewhere in it's life it was repowered with the flathead 4 cylinder that's in it now. Lot's of things could be altered in the 50 some years these things have been around.
A big THANK YOU goes out to BioTex for posting the chart!!!
Hope this helps,
Old Willy