Q Measurement Questions

I'm trying to calculate the parallel resistance and verify the series resistance for an inductor. The properties are below, provided by the manufacturer.



(Please ignore the parallel resistance value to begin with, that was my calculation and could be wrong)

The LCR meter they used ran at 100Hz, and using the equation



I derived a value of 17.7



Which isn't that close to the RS value they've supplied.

My ultimate goal is to know the resistances here:



The tricky part is Rgp.

Questions:

1. Why is my 17.7 figure so far out from the 10 they've supplied?
2. How come the 10-17.7 value is so far off from the actual resistance (3.7)?
3. How to calculate the parallel resistance from the data they've supplied?

I get Rp = 2.55K

From Motorola AN267:

I'm unsure. The value I have from another document for a less efficient but otherwise similar generator is 55 ohm.

I can't see how Rgp can be derived. Rgs is from on the windings, Rgp is eddies in the core - how can it be calculated from inductance and winding/series resistance?