Let me chime in with yet a 3rd interpretation of reserve responsibilities on a 24 in 7 rest period. Maybe someone can call the office and find out the right answer.

I think Uncle Sam is right on this part:
An assigned 24 hour rest period is different than a "last non-fly day".
There's no "1500" schedule check. During that 24 hours you don't have ANY obligation to answer the phone or check your schedule at all.

We differ on when you might be required to report following your rest:
If they haven't pre-assigned something and had you acknowledge it prior to that 24 hours then you just become a long call pilot at the end. Regular 12 hour leash.
It is legal for them to pre-assign a trip or short call to follow your 24 hours. ie= they call you and say you're on 24 hours rest starting 3:00 PM Tuesday and you have a trip that reports at 3:01 PM Wednesday.