Can be done via bruteforcing the phone numbers for half of the puzzles, only because one thing wasn't as clear in the game. Hint: If you have the crowbar and understand the treasure map, the location where you use the crowbar is very specific on what spot its interacted with.
Non spoiler mode: For those who didn't understand the letters you were collecting, the first part of the statement is past the yellow gate when you start the game.
I thought it would be clever.