I got it to work! I managed to open the file by unpacking it with ArcFSr.
Then, using !Edit I tweaked line 560 of the BASIC Chocks Away file to direct it to the correct directory.

Easy when you know how, eh?
And good gosh is the demo hard. The environment is swarming with enemies.

DO you see the possibility to get this as an adf and send it to me for the site?

You have mail, Wocki. :)