The signs are there on latest GSV view of October 2024, but are closed, either because the traffic order was not yet ready, or they close the signs out of school terms. If you look at your photos, you can see the line of the vertical hinge.
You turned right into the restriction. I see no advance warning signs present. Essentially, you have to prove the signage is "inadequate". Councils have a duty under Regulation 18 of The Local Authorities’ Traffic Orders (Procedure) (England and Wales) Regulations 1996 to place adequate signage to announce a restrition to motorists. Problem is this is subjective, your 'inadequate' is the council's 'adequate', so you can only get an independent view from a London Tribunals adjudicator, who will decide one way or the other.
