Not every character has its Shell Bone script. Either some charaters were not exist at 3000 years ago, or lost in the long time because of wars, disasters, and many other reasons in the long years. Big Seal script was earlier than Small Seal script, is one of the oldest scripts.
Its Small Seal script is
Both are very like the Chinese Lute, very pictography.
The Clerical Script is
The top part is same, but the bottom part changed completely. The character is not very pictography any more. The bottom part actually is the pronunciation part, determining the pronunciation of the character. Even though the character is pronounced Qin1，not the same as the bottom part 今 （Jin1). But we can guess with confidence that the pronunciation was the same 2000 years ago (but we don't know which pronunciation was) , but one or both characters have changed in pronunciation during ~ 2000 years.
Both traditional and simplified character is
Its Pinyin is "Qin2".