Hello Lynn
Both those photos are of the Vickers Light Tank sprockets. The newly machined one is from Colin Jones showing his handiwork while the cropped image of a brightly painted vehicle is from a museum.
Another photo from Colin's progress showing the attachment point for the light tank sprocket
My intention overall was to confirm that the sprockets and bogies are the same diameter for both the VI light tanks and carrier which I believe has already been established. The reason for wanting to know actual diameters is to ascertain how accurate the scale kit manufactures have provided for these two particular subjects.