Red Suitcase Lock

Overview
There is a red suitcase in the room with many empty pockets. Only one pocket seems to have something in it (a luggage tag from the China Pics trip), however it locked.

The lock needs a 4 letter combination.

Each wheel, from top to bottom, has the following letters on it:
 * Letter 1: B D J L M N P R S T
 * Letter 2: A E H I L O R T U Y
 * Letter 3: A C D E L N O R S T
 * Letter 4: D E H L N K R S T Y

Potential Lock Combinations of Interest

 * PUNS - Because the China album was full of cheesy puns and dad jokes
 * DICE - Team Nun's Bullzai indexed each photo's caption with the date (not month) of the photo. Putting these in chronological order started with the D (the only letter that was capitalized), gives DICE. Team Gimel's Gojiratoho found that this correlates better with the Chinese calendar, where the year begins in our Late January/Early February.
 * JIAN - The 4 markings on the plates from China form the word "Jian" which is a counting word for "luggage". This likely corresponds to the luggage lock and is a valid combination. (Credit to harlesbarkley / Shin)