I'm not seeing the values you got.
From the chart, -6dB is supposed to be 25.1% of the original inductance or 0.8283mH. That would certainly be closer to half the wire than what I made, there's many layers on that 2.5mH I started with, and only one layer on top to get to 3.3mH. It looks like you subtracted 25.1% to get 74.9% of 3.3mH, or 2.4717mH.
I read "% of original inductance" to mean the end goal, not the amount to remove from the original inductance.
By my reading:
-8dB is 15.8% or 0.5214mH.
-10dB is 10% or 0.33mH.
If you look at the notes under the model, the -10dB value is in fact listed. (-10dB is 330 micro Henries = 0.33 milli Henries)
Using that chart, I think it would be fun to build a 3110A with a few different steps. -6, -8, -10 could be -1, -2, -3, -6, -9, or maybe for testing, all of the them!
I'll be looking for some more wire now.