These cameras came in a wide variety of models; the one on the left is a Kodak Autograpic Special VPK and the one on the right is an early Kodak Special VPK.
You can tell, at a glance that the one on the left is a special as it has the Morocco leather covering to the body. With few exceptions the leather meant "special" from 1917 to 1926.
The one on the right looks like the "Regular" version (Kodak's description), as it has the glossy black* enamel body but the camera had a faster lens than usual and came with a gift case. It appeared for one year only in the 1914 catalogue.
I have used the Kodak catalogues in an attempt to date and identify them. This is very difficult as the same printer's plates were used for several years, even though details of the models have changed. To add to the fun, the cameras have a very simple construction and naughty people will often make one reasonably good one out of two dud ones. This means that parts from different years will be muddled up and confuse people. It would be nice to find one in the original box, with the receipt (dated and with the serial number) and instruction book...
* Be warned, the black enamel is very easily scratched, probably because of it age.
Kodak VPKKodak Vest Pocket Kodak