Lee, here's what the 2003 and 2004 screenplays/shooting script says about the number of the mailbox, and the garbage - just as in the prop book:
167 EXT: RIVERTON, WYOMING: DEL MAR TRAILER HOUSE: AFTERNOON: 1984: 167
The wind, as ever, blows.
ENNIS'S modest little trailer house, his battered pickup parked in front.
A new mailbox on the trailer house just to the right of the front door. ENNIS has a set of stick-on numbers in his hand. Peels the One off and precisely applies it, then the Seven: Seventeen. Steps back, admires his work. Walks around the side of the trailer to the driveway. Undoes a bungee cord on a dirty metal garbage can, throws the remaining numbers into the trash. Looks up.
Did you notice if the prop book identifies the small bag on the bed inside the trailer?
Does it call it a manbag? saddlebag? or Juniors bag?
Curious minds would like to know Lee.