Welcome and congratulations. In my estimation you are in great shape. For what you are getting, I would throw my thousand dollars down in a heartbeat.
Somebody cared enough to install rockguard and put a new axle under it, and it's not going to surprise me much if you find that everything works and in the end you just need to clean it up, make a few repairs, and think about painting the exterior.
I paid appreciably more and have more work to do, and less to work with, so there ya go, to me you scored. Enjoy !