Pi3 Jessie lite reboot hang

[PlanB]

I've been using a Jessie lite OS for over a year now but lately it is prone to hang on reboot, always with the same 6 lines.
[ OK } Started Show Plymouth Reboot Screen
[ OK ] Stopped target Network
Stopping dhcpcd on all interfaces...
[ OK ] Stopped target Remote target File Systems
[ OK ] Stopped target Remote target File Systems (Pre).
[ OK ] Stopped dhcpcd on all interfaces.
I've tried different PIs & SD cards, so it's presumably something I've changed? I've googled around a bit but reboot hang causes seem varied & complex. Are the above lines whispering loudly something I'm missing in terms of fixing the problem?

[LTolledo]

No plans on trying Stretch lite?

[PlanB]

Upgrading from Wheezy was so traumatic, I was hoping to get a bit more mileage out this 'un before the next wrench.

[PlanB]

Nov 9 11:59:02 raspberrypi kernel: [ 408.805131] sierra ttyUSB3: Sierra USB modem converter now disconnected from ttyUSB3
Nov 9 11:59:02 raspberrypi kernel: [ 408.805204] sierNov 9 11:52:00 raspberrypi rsyslogd: [origin software="rsyslogd" swVersion="8.4.2" x-pid="420" x-info="http://www.rsyslog.com"] start
Nov 9 11:52:00 raspberrypi kernel: [ 0.000000] Booting Linux on physical CPU 0x0

Syslog entries should be in chronological order right? Looks like after I unplugged the cell modem at 11:59:02 it was going to say something more but never got past the first 4 letters. Then it would have me believe it did a reboot 7 mins earlier? I'm so confused!