Thanks guys. Here's a screenshot from the JH Engineering page that says the series one has the ball bearings and the series 2 has the tapered rollers. Also by their account both of my axle flanges, though different, have the tabs for the calipers which indicate series 2, but the 3.54 case is finned, which indicates series 1.
The brake rotors and calipers are interchangeable between the two.