Mounting and component holder apparatuses and assemblies for holding rigid components

An apparatus for holding a rigid component in a downhole bore or a downhole collar based application, the apparatus comprising:

• a first support;
• first and second connecting interfaces extending on opposite lateral sides of said first support;
• first and second component mounts on at least one of said first support, and respective ones of said first and second connecting interfaces, said first and second component mounts defining a mounting plane spaced apart from said first support and operable to hold a rigid component in said mounting plane, wherein said first and second connecting interfaces define respective first and second planar contacting surfaces disposed at negative and positive angles respectively to said mounting plane, and wherein said first and second connecting interfaces have first and second connectors respectively for connecting said first and second planar contacting surfaces in a contacting engagement to corresponding planar contacting surfaces of one or more adjacent similar apparatuses.