Congratulations! As you can tell from my screen name, I like 139s. We had an old 2003 T139 and then later bought a new 2012 X139. It looks exactly like the one at the very top of this page. Yours looks to be in great shape -- was it stored indoors??
Be sure to ask lots of questions -- us old timers like to answer them!
You may find this blog useful -- it is all about modifications to the 139 series:
The LMIC (Look Mom I'm Camping)
And this blog may be of interest, although it is mostly about travel in the western part of North America:
Look, Mom, We're Camping!