Community Banks Plan Merger: Covina-based California State Bank will purchase Landmark Bancorp of La Habra in a cash and stock deal, according to a definitive agreement by the two companies. Landmark shareholders will receive $19.75 a share--$7.75 in cash plus $12 worth of California State stock, according to the announcement, which was made after the close of the markets. Landmark shares closed at $16.75, down 19 cents, in over-the-counter trading; California State stock last traded at $14 a share Thursday. Landmark operates six offices, all in Orange County, and had assets of $242 million as of Sept. 30. California State Bank has 14 offices in Los Angeles and Orange counties and assets of $482 million.