I found an early version of Sketchup.  Version 6.  The only problem is that it saves the drawings as .skp.   The website is
oldversion.com.  It has earlier versions but listed as Beta.  I don't know if they will save in another format such as .dat or .ovl.

You'd need a program to convert files to those formats as neither are used by Sketchup or Autodesk programs natively (as far as I know anyway).

I've tried a number of programs and so far none recognize  the skd extention.  Has anyone got any suggestions.  The version I have is easy to use and can create a number of Custom scenerys.  just can't use them until you can convert.

I literally know nothing about making programs or converters, anyone know how hard it would be to make a converter to get to the final .ovl? Or know anyone who could make one? This would be awesome if we could find a way to get to the final product! I'm going to go grab a copy of that version of sketchup, thanks for the info btw!