A friend of mine came across these at a garage sale and made copies for me. The CAVC one is dissimilar from the other two and appears to be of much newer construction. The folks at the Antique Road Show consider them to be curios from at least the late 1930s. Perhaps my gentle readers can contribute their ideas on them as well. They do seem to be the real McCoy at first glance.
Here’s the one marked BVA. The date on back is illegible.
Lastly , the newest by far is the one marked CAVC: