It seems according to Abaya challenge on Rava from the braisa....
1. The raisha of braisa besides seeming to support Rava in that a tmura found after schita is offered as a shelamim, it also contradicts the saifa of braisa, according to Abaye explanation of hoo.. That tmura found after schita is not offered as shelamim
I use Artscroll, so even reading Rashi at times is challenging
I am sure I am missing a small nuance here
Thank you,
dovid, boca raton USA
Rava (or Rabah) explains that when Rebbi Akiva says, "v'Chen Temuraso Achar Shechitas ha'Pesach," he means that both the animal was found and the Temurah took place after the Shechitah of the second lamb, but not if it was found before the Shechitah of the second lamb.
Abaye questions him from the Beraisa which learns from "Im Kesev" that a Temuras Pesach after Pesach is offered on the Mizbe'ach. If the Tana is referring to where the Pesach was also found after Shechitah of the second lamb, it would be obvious that one may bring the Temurah, since it is a straightforward case of Mosar ha'Pesach. Consequently, he concludes, the Tana must be speaking about a case where the lost Pesach was found before the second lamb was slaughtered, a Kashya on Rava.
I hope that this helps solve your problem.
B'Virchas Kol Tuv,
Eliezer Chrysler