47-55.1 Cowl Repair, How far to disassemble?

[Dongray]

I have some rust holes on the inner and outer cowls that needs fixin but am debating about how far to tear it down. Most of the inner and outer cowls on the passengers side arent bad but when I look down between them there is a hole in the bottom and some surface rust throughout (see pictures). The 4th picture is of the drivers side between the cowls.
My questions is should I just take care of the rust holes on the inner cowl and the bottom of the outer cowl or should I remove a large section of both so the interior can be sandblasted then install new inner and outer cowls? Thoughts?