I encourage SENDIAS too. But I also develop a list of provisions (in the borough and neighbouring boroughs) that could support them and hand them directly to parents with all contact details and my point of view of why the school may be a good setting for their child. I request for them to make contact, go and visit and rule out those that they do not like. Then I cc in all stake holders and let them know the choices of the parents and request for SEND LA to consult the schools.
It ends up that we are doing all the work for the LA but we are supporting parent and children in doing so.