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
20211025_163417.jpg
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.