Reading Lpad circuit with 120/240Ti

[DavidF]

Could someone help interpreting the Lpad high and mid circuit with the 120Ti/240Ti?

I note in another source that the switches are double-pole-double-throw. I read this on the mid 120Ti network as “a” circuit with 2.4 ohms plus 1.2 ohms in series, 15 ohms parallel. The “b” circuit bypasses the 1.2/15 section and thus 2.4 ohms series, and 27 ohms parallel.

Comments appreciated,
DavidF