Reply to "Problem with door jam latch"

Just to follow up, the nut plate is held on with a capture type sheet metal piece that allows the plate to move so you can adjust the catch. Most likely the tin has dissolved which is why the nut plate dropped. Now if the bottom the post is gone because of rust, the plate is in the rocker.

One item of future advise, drill the heads of the screws off and the catch will just pop off leaving the length of the screws intact. If the nut plate mount is rotted off, the remaining studs will keep it from dropping and then you can cut through the top of the post and weld on a holding tab for the future. Then you can take your time using penetrating oil and work the remaining studs out with vise grips.

Take a close look at the post bottom to see if it is still intact or totaled. You may need to pull the rocker or at least cut off the top sill to access the post bottom. You should remove the radius transition from the rocker to the latch skin where the alignment bezel fits anyway because it is a water and dirt trap and will be bad. This is what you may find.