Pensions - IHT409 form question

Acebiros

My younger sister died aged 52 in April and I am dealing with her estate. 
She had three private pensions:
NHS
Teachers Pension
USS

The NHS and Teachers Pensions were both commuted just over a year before she died.
The USS pension has just paid out a discretionary death benefit sum to her estate (via me as the Executor)

I am stumped as to how to deal with these on the IHT409. I understand that I'll need a separate form for each pension but do I need to complete the form for the fully commuted pensions, which went towards paying off her mortgage with residual funds in her bank account?