According to my parts book, the H190 diff in the 4 speed wagon came with a 3.89 to 1 ratio. [35/9]
This might be quite good for cruising, but may not be the hot setup for hillclimbing.

The front calipers from the late 200B [810] [Girlock] use the same pads & repair kit as the series 1 Bluebird only the caliper mounting lugs were diferent. If you use the serirs 1 rear disc brake setup, then modified 200B struts with these brakes will mean that the brakes match front & rear. The 200B master cylinder has the same specs as the series 1 master cylinder, even though it looks completely diferent. The booster is much smaller on the 200B & this may mean that it is a better proposition to adapt to a 1200. The pressure bias, front to rear, on the 200B & the series 1 Bluebird is 450lbs, while the series 2 Bluebird has a 550lb bias.