Total primary inductance was actually measured at current flowing thru both primaries connected in series. The current was then doubled in order to correct for the mmf when using one primary winding only.
5V/50Hz was superimposed upon a swept DC voltage and the resulting ac and dc current was then added. The ac contribution only affected the two first measured points and was then always less than 10% of total "DC" current.
Due to the fact that the magnetic field intensity is approximately 14A/m per mA unbalance, it is obvious that this type of un-gaped core is most suitable for pure Class A push-pull operation. However, the above results also implies that some Class AB or even single-end Class A operation is possible.
In view of the L(U) dependency, I reserve myself for some discrepancies regarding small "low resolution" current measurements.