Poop

Willard and I recalled that S&W 59 magazines worked in the Daewoo DP-51.

We cannot check that because the DP-51 has hidden itself from human sight.

Willard could lay hands on a DP-51 magazine, so he wondered if it would work in a S&W 59.

It does not.

The floorplate hits the front strap before the magazine latch can grab the hole.  The holes look identical and appear to be spaced identically from the mouth of the magazine.

So I checked it on a Marlin Camp Carbine.

Also no-go.  The latch never latches.

Oh well.

DP-51 on left:

The S&W magazine's hole is just a bit closer to the mouth of the mag.  That's why the DP-51 won't lock into the Marlin.