T-46 Long Lock

[LJPB]

Hello! I recently locked an old trunk by accident labeled "T-46 (i believe) Long Lock" that I do not have a key for. After attempting to pick it, I searched for advice online and found a key that seemed to be made for this lock. I got the key today and have not been able to unlock the trunk using it. They key, when facing outwards, is able to turn the lock about 90 degrees. Is there a way to make this key work or for someone with no lock picking experience to pick it? I would highly appreciate any help that I can get on this topic!

Here are a few photographs
the lock itself
the labeling
key

[globallockytoo]

My guess is the key wont turn at all, right?

Insert key as far as it goes, mark on the neck where the edge of the front of the keyhole is. That is where you need to file using a 4" warding file.

[smokingman]

You should only file the key on the top so that it can pass through the circular ward (rim) that is visible at the front.
You will be able to see when it is deep enough by trying it as you go.
Go slow.

[keymaster1053]

on that type of lock, the key isn't intended to completely turn all the way around to the starting position. when you turn it as far as it will go, try pulling gently while nudging it back and forth. it may just be a tight fit.
keymaster