USN shovel covers M1910

[RCS]

I think these covers are both the Model 1910 and both are USN ship marked. The cover on the left is also marked USMC and the belt hanger is at an angle as compared to the cover at the right.

Is there a reason for the belt hanger to be at an angle ?

[5MadFarmers]

Both are WW1 era. Those covers were made in 3 different eras: pre-1910, WW1, and WW2. Those are WW1.