Ok, I found some hints online and got the job done. Gotta say, the service manual is sorely lacking in detail when it comes to disassembly and adjustment of the front brake. Specifically the initial adjustment of the master and slave arms after disassembly.
Major problem is very very few people have experience of DLS/TLS (dual/twin leading shoe) brakes, discs have been normal on most 'larger' bikes for over 50 years now, lower power bikes use SLS (single leading shoe)
Probably the easiest (but slowest) method is to turn cam so springs are fully extended, put washers between spring coils, turn cam back and remove it, then, do the same for the other cam. With both springs removed it's easy to swivel shoes to slide off pins.
I always left link rod 'loose, pull lever so one shoe is in hard contact with drum (tie it to bar) then used an adjustable wrench to move the second lever into contact and adjust link for zero slack.
It worked on everything, Honda, Suzuki and Yamaha (don't remember ever doing a Kawasaki, they were probably the first to use disc brakes on 'smaller' bikes (250,350,400, 500 triples)
70's Triumphs with cable and spring between operating arms was always the easiest although it was frequently necessary to strip down and re-grease pivots so both shoes contacted drum properly, things could get 'interesting' if one shoe bit then the other slightly later just after you panicked and pulled a LOT harder
