@enuddleyarbl,
If you don't mind me commenting. If you're going to be reading these books on your Kobo Forma then very little of what you have in that body style is going to be useful.
In my experience (with my Kobo-centric hat on):
- padding will default to zero anyway
- widows, orphans - in kepubs, both are ignored
- widows, orphans - in epubs, these values can be set in the Kobo config file
- border-width, height - no idea why you need these at all in body
Personally I don't specify margin in the body style, but it's probably harmless because the Kobo's own settings for left/right will take over.