I don't have the Unagi Magnetics website set up yet, but you can pick transformers up together with a D.I. daughter board on the Conspiracy to Commit Electronics website
here, just select "XLR DI w/ Transformer" from the dropdown.
I have a datasheet for the transformer that I put together, but I haven't formalized it and posted it anywhere yet.
I guess I should probably add that to the disclaimer on my signature, owner of Sushi Box FX, Conspiracy to Commit Electronics, and
now also Unagi Magnetics.