Yeah dd you're pretty close there ! I have just fitted bluebird rear discs to my coupe with a H145 diff. Not yet hit the track to test them out but the only challenges of note were :
Stupid Datsun idea of retaining axles with the brake backing plate means removal of bearings !! (Bluebird having longer axle means no swappy to 1200 housing)
Disc backing plates bolt straight up
Solid brake line over housing has to be shortened and changed to a single flare end - drum set up uses double flare.
Unless I am mistaken (I cringe at the possible wrath of the dattomasters) the restrictor has to be removed from the drum brake master to allow the necessary increase in line pressure.
USE 14" wheels or better !! I managed (after much searching and stress and cussing) to use 13" but probably out of the realm of any sane person .
Will post some pics soon and let you know how it went.
P.S. Used stanza struts and brakes so it is all a matched set so to speak.
Cheers