If the lower earner gets it at 62, then what happens if the higher earner passes away say at 72?

It's in my spreadsheet. dropbox.com: Spreadsheet

Survivor rules
He *did* file before death. "Early" means before FRA (normally 66).

Filed early Larger of his reduced benefit OR 82.5% of his FRA amount
Not early: Her reduced spousal benefit (based on her age) applied to his increased amount

He did *not* file before death:
Died early: His FRA amount
Not early: Her reduced spousal benefit applied to the amount he would have gotten if he filed at date of death.

and

Widow benefit base:
If he filed early His reduced benefit., but not more than 82.5% of his FRA benefit. ( 13 months of reduction)
If he filed not early His benefit (perhaps bumped up.)
Not filed, died early His FRA benefit
Not filed, no die early His benefit at date of death (perhaps bumped up.)

Widow benefit reduction, based on her age vs. 66
Widow benefit base reduced by # of months before she is 66.
No increase past 66.