Wastelander note is a paper note leading to John's treasure box in the scrapyard.
Location
It is found, together with John's key, on John's body, in the random encounter More Than Just Scrap.
Transcript
Billy,
I'm sorry I stole it. You deserve to have it back. Remember the old scrapyard, north of the Bethesda ruins? Look in the burned out bus in the northwest corner. Near an old red boxcar.
Tell Loreen I still love her, and I'm sorry for everything. I hope somebody finds this before the buzzards tear it to pieces.
Your loving brother,
John
