The above allowed me to correctly get a clone of the repo, make the change, and push back to gerrit.
I confirmed that the changes were in place by again pulling from All-Projects in a new repo and checking the change appeared in the git log.
However, under the Access panel on the Gerrit GUI, there is still no reference to a Verified label, only Code Review.
I stopped the gerrit server and started it again to ensure it re-read any config, but with no change.
I added the Verified label definition as per instructions here:
The tail of project.config now looks like this:
[label "Code-Review"]
function = MaxWithBlock
copyMinScore = true
value = -2 Do not submit
value = -1 I would prefer that you didn't submit this
value = 0 No score
value = +1 Looks good to me, but someone else must approve
value = +2 Looks good to me, approved
[label "Verified"]
function = MaxWithBlock
value = -1 Fails
value = 0 No score
value = +1 Verified
Cheers,
Tom