I am also waiting for a few folks to bring the comparitive samples. I ran the 'scope through Cal. What a PItA, and it was OK...and within specification( for an older 100 MHz Tek ). The VOM was quite simple by comparison...:)

I too need a means of mounting them. I think some Cu buss bar bent to shape over the core and bolted to a thicker piece of Cu will do it. Cu gets pretty hard when worked, no?

Looking forward to hearing your impression of the amprphous. That material is VERY nice, even compared to some other exotics. I may try some 7% Si lamination. I know a source, and it ought to be relatively simple to get the core free. Higher perm, and lower loss than 3.5% Si.
cheers,
Douglas