life and death: 2 x 4 in the corner with defects

Question

In a go game (with another 4K) I got a 2 x 4 region in the corner with lots of defects.

W1 almost surely will happen. Can White get life or ko?

$$Wm1
$$ |------------
$$ | . . . . X . 
$$ | . . O X . . 
$$ | . . O O X . 
$$ | . . O X . . 
$$ | . 1 O X . . 
$$ | . B X X . . 
$$ | . . . . . . 

Answer 1

I'm tempted to say its either ko or seki, black's choice.

$$Bm1
$$ |------------
$$ | . 2 1 . X . 
$$ | . 3 O X . . 
$$ | . . O O X . 
$$ | . . O X . . 
$$ | . O O X . . 
$$ | . X X X . . 
$$ | . . . . . . 

W2 is the only move, and B3 enters the ko.

$$Bm1
$$ |------------
$$ | . 2 1 . X . 
$$ | 3 . O X . . 
$$ | . . O O X . 
$$ | 4 . O X . . 
$$ | . O O X . . 
$$ | . X X X . . 
$$ | . . . . . . 

B3 fails, it ends in white life by W4.

$$Bm1
$$ |------------
$$ | 3 O X . X . 
$$ | X 1 O X . . 
$$ | 4 2 O O X . 
$$ | O . O X . . 
$$ | . O O X . . 
$$ | . X X X . . 
$$ | . . . . . . 

Not even a ko. If B1 at 2, W1 is seki.

$$Bm1
$$ |------------
$$ | . O X . X . 
$$ | 2 6 O X . . 
$$ | 4 5 O O X . 
$$ | 1 . O X . . 
$$ | 3 O O X . . 
$$ | . X X X . . 
$$ | . . . . . . 

1 is vital, but playing it directly doesn't work.

$$Bm1
$$ |------------
$$ | . O X a X . 
$$ | 2 . O X . . 
$$ | 1 . O O X . 
$$ | 4 5 O X . . 
$$ | 3 O O X . . 
$$ | . X X X . . 
$$ | . . . . . . 

If 1 and 2, it becomes a ko (at a).

$$Bm1
$$ |------------
$$ | . O X . X . 
$$ | . a O X . . 
$$ | 1 b O O X . 
$$ | 2 . O X . . 
$$ | . O O X . . 
$$ | . X X X . . 
$$ | . . . . . . 

White should instead answer B1 at 2, then a and b are miai for direct life.