I would sincerely suggest if the Caravel
is intact and the skin (outside body) is in good shape and the inside parts are all there, working or not, it will be snapped up by someone! Floors are always a problem with older Airstreams. Weak spot. Some folks have been lucky and been able to partially replace their floor by a section here and there. We did a complete frame off because all of our floor was rotten.
Take a ice pick or screwdriver and poke around under all the cabinets, etc. to see if it feels soft or spongy. If the spot you have the picture is any indication, it probably needs replacing. But, could be just one place. The entrance by the door is often an indicator when you step in does it feel really solid?
Here is my husband's thread on replacing our floor. It is lengthy, but has lots of pictures. Maybe it will be of help.
Mrs. NorCal Bambi (traveling in S Tardis)