NoID Oncidium in need! How do I care for it?

[SillyCookies]

Hello everyone,

I bought this Oncidium from a flower shop, but it turns out that the roots were in a terrible state and it is now pretty much rootless. I want to know how I can optimise it's chances of recovery, but I'm realising how varied the Oncidium alliance can be and am not entirely sure what the best thing to do is. I hope someone can help me, I really like the flowers on this one

So I realise that an exact ID is too much to ask for (I have googled extensively and found far too many similar but different looking orchids), but I'm hoping that I can at least get a confirmation on the type of orchid and the care it requires. Currently I'm thinking it's an Wilsonara/Oncostele, or an Odontocidium.