Have you tried searching your C: drive for files ending in oolite-save? The older versions used to be installed by default inside C:\Program Files\Oolite, while the new ones are installed in C:\Oolite. My guess is that you will probably find your saves inside C:\Program Files\Oolite\oolite.app\oolite-saves.
In any case, all of the Oolite installer versions I can think of do not overwrite existing saved files, so I am reasonably confident that your savefile is still somewhere in your hard disk. Best thing would be to locate it manually and then copy it over to the new oolite-saves folder.
found the old installation in program flies (x86) - i had looked in the 'normal' prog files
anyway the old installation still finds my last save
onto find some pirates - thanks for all the help chaps