Is there any way to restore a prior save in these games. I am at World 9, finished all rooms including the last one. According to the walkthrough I've done everything I should,... I have found everthing ...I have nothing left in my inventory to do anything, the only hot spot I can find is the flamable water
but I no longer have the flame thrower.
I lit the oily water earlier and then left the room without completeing it When I went back I finished it but I can't move on.

Any suggestions?

Ernestine, there is no way to go back to a save since it autosaves over itself. Have you checked if the flame thrower is back where it was originally?