Thermal noise of RD/RS?

[gjcoram]

The thermal noise is computed from
S_thermal = 4 * `P_K * T * Gn;
and I don't see any contributions from the source or drain resistors.

[dwarning]

Perhaps it is a total misunderstanding of the model code, but I see not any inner node and separate branches for drain and source resistors. So we have no gain reduction and also no thermal noise contribution of resistors.
The Verilog-A code seems a stripped down version of post 2.6 version model.