Hi,
As the film was on T.V here in the UK yesterday, it reminded me that in the past I'd looked at the loading routines to see if an AtariMax 8Mb version would have been possible.
Instead I have simply hacked in a small routine to offset the appropriate 'disk/side' into the single ATR and remove the message asking to insert the correct disk.
Following an online walkthrough I was able to complete the game. There is still work to do as the game save / load to a blank disk that is initialised