[tevake]

Some things to check out in your new trailer.
Look for leaks, seams can be resealed. Leaks will rot the floors. Very common issue.

Replace the converter/ charge controller. Old ones are a fire risk and don't regulate charge rate like modern ones. Bad for batts.

Check out frame in the back of trailer, known to separate from floor.

And the axel will most likely need replaced as rubber parts fail at about 25/30 years, resulting very rough ride
Leading to leaks and other wear and tear on interior parts.

My motorhome came with driveline vibration that caused problems in the cabinets attachments to the shell, since sorted and repaired.

The shell of your looks to be in exceptional condition. If the floors and interior are as nice then you really did score! These things mentioned above are regular maintaince and up grades.

Do you have pics of the interior?

Cheers Richard