He had to sign his whole name, Martin Pawley. He couldn't write just Marty!
7 seconds sound clip from the The Searchers (1956) movie soundboard.
You can hear this line at 01:16:39 in the Blu-ray version of the movie.
Quote context
[...]
- I am sorry, I won't be back for Christmas again this year.
- I set pencil aside and hope you are enjoying good health and your folks the same.
- I remain, respectfully, yours truly, Martin Pawley.
- They'll never find that girl. Never!
- He had to sign his whole name, Martin Pawley. He couldn't write just Marty!
- I don't care if he never comes back!
- Charlie, you stay for supper. I won't take no for an answer.
- The thought of saying no never entered my head.
- Ain't no place I'd rather be than right here right now.
[...]