These files are definitely not made with KiCad. They also look prehistoric, with painted zones and such. I guess these were made over 20 years ago. And a quick check shows file dates of 1998-08-25, so indeed 25 years ago.
Geda’s Gerbv can not load these files at all and gives thousands of errors about Undefined D-codes
The errors themselves seem to be mostly for D11, D39 and D42. You can try hacking into the gerber files with a text editor in an attempt to define these codes but I don’t know if it’s worth the effort.
You can follow the tutorial below. Stuff imported from gerber files is inherently missing a lot of information, and therefore I replaced most of the back imported items from the Gerbers by KiCad native entities (such as footprints) anyway. Your painted zones are also ancient and also have to be replaced / recreated to be able to work with it in KiCad. By back importing it to KiCad you can recover some things, such as PCB outline, location of mounting holes and footprints and an indication where other things are or should be. But a lot has changed in these 25 years and it will require some effort to make something decent out of this.