Characteristics of HP-IL Transformers?

[Martin Hepperle]

@Hans:
That sounds very promising. Do you think the cores must be of the toroid shape? Manually threading 100-200 turns through them does not sound like a fun evening... except there is some magic involved.
Could they not be replaced by a straight or a split core type which allows for easier winding?

@Dave:
Did your receive the datasheet? Would be interesting for comparison.