OK, fixed this... In Writer's Base.php, I've changed:
This should lead to a much more consistent experience across different versions of Word, but will break things horribly for existing code. Windows Word 2010 appears to scale 96 pixels to an inch, and taking a wild guess I'd say Mac Word 2011 scales
72 pixels to an inch.
Would a more sensible approach be to print in inches, but to do a 96px = 1in conversion in Style/Image.php?