All I know is that they're less standardised than JJ2's in the sense that most events were made to accompany a single level. Like the stompers, umbrella's, and the Battery Boss. JJ2 only has some minor events (such as poles, bumpers, snow, etc) that relied on specific tilesets.

That said, I neither have any idea what palette entries are used by the common sprites such as Batteryman and the Suckers. Getting those to work would at least kickstart a custom tileset.