Windfalls and buafroo, thank you both. I will look at that link today.
Looking closer at the documents we submitted to the Tribunal in France, we did submit the Placement Order. So they had sight of that as well.
AUK - have forwarded me a link on how to find a solicitor in from the law society and the Coram Legal Advice service (sadly this service doesn't look suitable for us, it seems to be focussed on children coming to the UK).
International Adoption Centre (IAC) - have forwarded me a list of Immigration Solicitors based in the UK who have experience with Adoption cases, but as an organisation they deal with children coming to the UK.
Our local Authority - suggested we might not need for the UK order to be recognised as the UK and France are signatories to the Hague Convention 1993, but would suggest professional legal advice.
French Embassy - sent a link to the Tribunal and couldn't offer further help or advice.
This is the update from our enquiries today. Not much to work on except to go for Legal Advice. I do wonder whether we are doing the right thing by submitting a case to the Tribunal, but from all the research we can see it seems that the Tribunal need to make a new judgement for our little one to become French as a dual citizen.