As far as case damage goes, that is fairly minor.
Dont get too worried yet. Strip ogffwhat is on it, and see if there is an actual hole or chunk missing.
When that is the case, often globs of repair material get pushed inside.
It appears the bottom case is OK, unless there is a small crack.
I know of a member on here that I gave advice to that split the cases, leaving the topend on. Then removed some trans parts, got upper case welded, resurfaced it himself (after a pep talk),and has A LEAK-FREE HAPPY MOTOR.... for less than the price of main bearings and gaskets.
Yours looks good, they often have chunks broken out on both cases..