Owner manuals are for sale from Helen Davis at 937-492-8885.
But just a heads up. There were no detailed "Service Manuals" available when your trailer was built. They became available in later years. The owners manual should have a line diagram though. My 65 has one.
Owners Manuals and Service Manuals are two different books.
-"You want to make it two inches - or, if you're working in centimeters, make sure it's enough centimeters for two inches."-Red Green