OK!
Some success!
If after booting (and not finding my USB tuner). If I unplug the tuner, then plug it back in; my dub/adaptor does indeed exist!
Then I service tvheadend restart
When works!!!
HD channels though seem to 'suddenly' developed a problem:
Mar 05 15:52:50 TS: Sony CXD2820R/West: 674,000 kHz/BBC HD: H264
#101: Continuity counter error, 995 duplicate log lines suppressed
Mar 05 15:52:50 TS: Sony CXD2820R/West: 674,000 kHz/BBC HD: AAC
#102: Continuity counter error, 117 duplicate log lines suppressed
Mar 05 15:52:50 TS: Sony CXD2820R/West: 674,000 kHz/BBC HD: Transport error indicator, 2698 duplicate log lines suppressed
Are there any issues/side effects from restarting tvheadend in this way????