I'm not clear what the first set of numbers represent, someone else may know...however, I can tell you about the second set.
First off, I believe the first "1" is actually an "I", it stands for International. This was an upgrade package that was offered, if you perform a search of "International upgrades" you'll see some earlier threads that discuss what this included.
Next the "31" is your length, this means you have a Sovereign, not an Ambassador which is confirmed by the Sovereign name plaque. An Ambassador is 29' long, a Sovereign is 31'. The "D" means, rear bath/double bed. The "9" is for the year, 1969. The "J" means it was built in Jackson Center Ohio and the "514" is the sequential serial number.
You can confirm this at this Airstream.com link:
Serial Number Identification Website
Now I guess you have to change your profile
Shari
