I can put a small amount of DC voltage (up to 12V or so) on the inductor / OPT under test, my HP 4276A LCZ bridge does allow selecting the measurement frequency, starting at 100Hz, and can apply a modest DC "bias" across the primary / inductor under measurement.
Dependin g on the actual device under test, I usually see only a little difference between "biased" and "unbiased" measurements.
I can get stable inductance readings up to 1 to 2 KHz, above that, the readings go "crazy", with increasing frequency.
It allows for setting the DC "bias" voltage, but I do not know what the actual current is - I suppose I can temporarily insert a DC milliameter in series with the OPT ' primary.
The RDH3 circuit looks reasonably easy to build, it would be interesting to see how it compares with an LCR / LCZ meter, which can test at 60 Hz..
Aother approach that I was thinking about, is to build up a simple low frequency audio oscillator, and use a simple L-C circuit consisting of the OPT primary, or choke, and capacitors of known value, measure the output frequency, and then do the math to determine the inductance value.
Kinda kludgey, but that should also work.
/ed B