I have the opportunity to pick up a ZKK 600 in 7x57. Every thing looks to be correct but the stock has a cheek piece. All of the pictures I can locate never feature a cheek piece. Colour, style, checkering etc. look to be correct and original and gun appears un-molestered. Can anyone clear this up for me? Was there a factory stock with cheek piece? Pictures or links to pictures would be appreciated.