Looks conclusive - having examined it closely it leaves no doubt that a lawful statement has been made thus:
“1. NOTICE IS HEREBY GIVEN that Lewisham Borough Council on 22nd May 2017 made the above-mentioned Order under sections 84(1)(a) and (2) of the Road Traffic Regulation Act 1984, which will come into operation on 1st June 2017.”
This is unquestionable evidence of the validity of the 20 mph controls for all motor vehicles in the borough.
Note the the language and tense - “made” and not “would be”.
It leaves only one question - why would a knowledgeable officer speculate to a member of the public about whether the 20 mph controls are enforceable ?
Perhaps he was being mischievous - will we ever know ?.
I would appeal for people to be reasonable - don’t exceed twenty mph - it’s not as if you are being required to restore the man with the red flag walking a few paces in front of you.