Any lock experts out there?

[E5 Charger]

I have a new trunk lock for my 74 and would like to key my glove box lock the same. The glove box lock has three brass tumblers and one silver one. The new key tag has the numbers 1,3,4,6 on the tag. Should the silver one be a number one? My silver one doesn't have number on it. I can't read the number on the brass one in the photo, so the only one I have is a #3 tumbler. Where can I buy these without buying an expensive package of 100. I may never need these again. I know I could take it to a locksmith, but wonder how many have the tumblers for our old cars.
I was examining my old rusty trunk lock and found something interesting. It is a different type of lock with pins in it, but mine is missing the pins! I've had this car since it was about three years old and remember when I got it my dad's key from his 74 Charger opened the trunk, but mine didn't open his. I wonder if it ever had pins in it from the factory?

[terrible one]

I'm no expert but will share what I have learned with my own endeavors

The numbers on the tag are a code that correlates to the depth of cuts for a locksmith to make a key, but the numbers of the code are not the depths. EP and ES lock codes use 6 different cut depths (how deep to cut each position, measured from the shoulder of the key) and they are as follows: 1= .246", 2=.266", 3=.286", 4=.306", 5=.326", 6=.346." The code on your tag, EP1346 decodes to 25214. The first number in the code is the cut closest to the head. Also the glovebox and console locks are the only ones with the flat/ wafer tumblers; doors and trunk all have pin tumblers (a more secure design)

From what I have seen taking apart glovebox and console locks, not many of the tumblers are numbered, lots of times they are blank. Also the silver tumbler is the retainer that keeps you from just pulling the lock out so you won't have to change that one. What I suggest is to swap the 3 tumblers around to where they are closest to corresponding with the key you want to use, then remove material as needed. Obviously you've disassembled the lock so you probably know it is easy to see the position of the tumblers with the bezel off of the lock. I take a very small file and either elongate the slot in the middle of the tumbler and/ or take material off of the end that sticks out/ keeps the cylinder from turning until they will clear

[E5 Charger]

Thanks for the advice terrible one. I'm a little nervous about screwing up the tumblers by removing too much and the lock not working with the new key. I may just live with two keys, since I never lock the glove box anyway. Or, maybe buy a matching set of locks and sell the trunk lock I have. I appreciate your answer and if I decide to buy a matching set may try filing them first.

[terrible one]

No problem at all. If you are leery of filing the tumblers and decide you don't want to have 2 different keys, I can look to see if I have a #2, #1, and #4 tumbler to send you. It will be at least a week until I can go look. Just let me know