Thanks for the response - its been awhile between posts, however if you see this here's some additional info:
Since seeing that behavior I've been able to reproduce the effect with various toroids (always of the tape-wound variety), also when checking the inductance I've used both 1Khz and...
While working on a project I noticed something wonky and I don't understand how or why it is happening.
Typically if I have an inductor, the presence of a permanent magnet will reduce the inductance according to its distance - however I have started using a type of nanocrystalline core that...