Robs,
When these vassals were made, I used .PNG format for most images, a better quality but takes up more space.
Also, many of the Across 5 Aprils vassals allow close ZOOM because of the size of the images - I personally hate Vassal modules that at maximum zoom and you can still barely read the counters.
Concerning separate files, I don't know how to make all Across 5 Aprils scenarios into ONE file, and besides I would have to convert all images to .GIF (or .JPG set at low size) to reduce size of files.
And sorry, it would not be worth my time and effort to do so - if someone would like to do so, please go ahead.
For future reference, why does it bother you the size of the Across 5 Aprils files?
http://www.vassalengine.org/wiki/Module:Across_5_AprilsStephen Oliver