Abstract: An improved lock mechanism comprising an anti-pry shield having a hollow body with a first end and a second end, and a cylindrical shield at its first end; a knob-set cylinder having a plug with a key end and a driver end; a monolithic cylinder guard having a body with a beveled exterior side wall between a first end and a second end, the second end having a bore, a cylinder receiver having a cavity open to the first end, the cavity adapted to receive the knob-set cylinder from the first end, the cavity open to the bore in the second end, the bore adapted to receive the key end of the plug; and a cover having a beveled exterior side wall between an open first end and a covered second end, the decorative cover permanently secured to and covering the beveled exterior side wall and the second end of the monolithic cylinder guard, the covered second end of the cover having a bore coaxial with the bore in the second end of the monolithic cylinder guard and the plug of the knob-set cylinder.