Other than a few details like the type of carpet on the walls and the upholstery on the cushions, they really haven't changed much over the years. Go into the sold archives here
and at fiberglass-rv-4sale.com
and look for other Casitas- don't have to be the same year- to get an idea of what yours looked like.
While you're looking, you might see some ideas to make it better than original!
Before you get too deeply into interior rehab, make sure you have a weather-tight shell sitting on a solid foundation. Check tires
(dates, not tread!), axle
, frame (rust, cracks), floor (soft spots), body-to-frame attachment (rusted bolts), leaks
(windows, door, vents, rivets).
Congratulations, and best wishes getting this one camp ready!
How about some pictures? Directions for uploading are in post #7 here.