I fixed the issue (I think), well, sfc scannow and dism restorehealth both now complete successfully...
I found in the cbs.log entries for missing packages, e.g.
Info CBS Repr:Not able to find matching update for package, Package_1853_for_KB....
I have a system with patches downloaded, so I located the kb's, extracted them and then applied them with..
DISM /Online /Add-Package /PackagePath:c:\temp\extractedfiles\Windows......cab
Then when I ran Dism /Online /Cleanup-Image /RestoreHealth it failed with the same error, but in the cbs.log, there were no longer any missing packages, the only issue was the one mentioned by the component scanner. (post yesterday at 10:12am)
In short, there were some missing files in the amd64_windowssearchengine_31bf3856ad364e35_7.0.14393.206_none_a8fd1df909a77469 folder inside the winsxs folder, in this instance I located the file on another server which had the same folder with more files in it, I ran ...
Dism /Online /Cleanup-Image /RestoreHealth /Source:\\otherserver\c$\windows\winsxs /LimitAccess
I watched as the command completed, the missing file popped into the folder, following which the restorehealth command succeeded.
