I do have a couple of old advertisements for the Brno ZKK's, but neither show the reverse view of the stocks. As Hunter4752001 says there was the 'standard' stock and the monte carlo stock. The monte carlo stock as in the image above would be the most logical style to suit a cheek piece whereas the standard stock style does not look as though it would have a cheek piece, I myself had a ZKK 30-06 with the standard stock and no cheek piece, had been re-barreled to 6.5-06 as per image below.