<Do you know how they were strengthened in the 2nd ?>
Not sure what it is you are looking for. A discussion of each new claim and how it could be asserted against infringers? I don't have the time to do it.
If claims were deleted as a result of reexamination, there would be no argument that the patent was weakened. Perhaps significantly.
Conversely, if new claims are added, why wouldn't one believe that the patent is therefore stronger?
For most of us, I think that explanation is sufficient.
Opty