happy to be have your thoughts Whools, as buggered if I know. As per other thread, parts list suggest disks are Mazda 323.(DBA930)
I found a sticking caliper yesterday after putting the disks back on, and figured may as well look as better braking options at the same time

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I figured the calipers are Girlock, and M16 by the stamping?

still haven't started it yet, but getting closer: