Identifying M1C straps era

[326thAEB]

I have just purchased what looks to be an unused set of post war M1C chinstraps. The metal clamps are green painted while the buckle and end keeper is blackened. The buckle is completely unmarked and the end keeper is the rounded type. Would these straps be considered late 1950s to pre 1965? If I understand correctly after 1965 the buckles began to be anchor marked for a period.

[326thAEB]

I forgot to add a photograph of the buckle

[326thAEB]

Some additional photos, although there is some slight staining the clamps appear to have never been bent 

[326thAEB]

Does anyone have any thoughts? I’ve been trying to pin point the era the last day or so but have not been able to turn up much my best guess is probably late 50s 

[Heptonic48]

To my knowledge Vietnam era M1c chinstraps either have the anchor or are unmarked. Those look like Vietnam era M1c chinstraps that are missing the ball end on the buckle, but idk why they have green painted metal clasps. Maybe someone used them from spare parts?

[326thAEB]

14 hours ago, Heptonic48 said:

To my knowledge Vietnam era M1c chinstraps either have the anchor or are unmarked. Those look like Vietnam era M1c chinstraps that are missing the ball end on the buckle, but idk why they have green painted metal clasps. Maybe someone used them from spare parts?

I know the earliest Vietnam era M1C chinstraps had green painted clasps and the buckle and end keeper were black, I couldn’t tell you why though. Maybe a transitional period? I am just trying to figure out how early these are