High permeability soft magnetic powder

Hi folks,

I need this stuff to fill between air gap due to poor technical cutting of c-cores to restore permeability. I'm winding an input transformer where I need to best of permeability from a nanocrystalline c-core.

Now I'm using 99.95% Iron powder from Merck which increases my permeability to 1.5 times, but it is not enough.

Where could I find something fancy like permalloy, iron-cobalt powder or iron powder annealed in hydrogen?

I could buy a cobalt-amorphous toroidal core and try grinding it down to powder, but that would probably destroy the permeability.