I should add, in further investigation on other OpenBSD 5.9 systems I've found one with,
/etc/group:_sndiop:*:110: /etc/master.passwd:_sndiop:*:110:110::0:0:sndio privileged user:/var/empty:/sbin/nologin so that does seem to be a clue. Rerunning sysmerge I seem to be getting all this sorted now. Sorry for the noise, I'll remember to retry that next time I run into such a puzzle! (It's even possible I lost track of where I was up to with each machine and omitted it altogether, sigh.) -- Mark
