Mounting system such as for vehicle lights

A mounting system for mounting of a spotlight or other item to a vehicle or other underlying support, the mounting system comprised in combination:

• a base having a rigid monolithic form including a cylindrical body with a flange extending downwardly from said cylindrical body;
• said flange including a plurality of bores passing therethrough;
• said cylindrical body having an upper face;
• a central recess extending down into said upper face with a floor defining a lower extent of said central recess;
• a plurality of holes extending downwardly into said upper face, outboard of said central recess;
• an adapter plate formed of rigid unitary material, said adapter plate including a main body with an ear extending laterally therefrom;
• said main body including a cylindrical extension sized to fit within said central recess in said cylindrical body of said base;
• said adapter plate including a mount hole passing through said ear;
• said main body including a central bore extending along a centerline thereof and through said cylindrical extension;
• said main body including a set hole on a side of said central bore opposite said ear, said set hole including a set pin therein;
• said set pin biased to extend downwardly from said set hole and into one of said holes in said upper face of said cylindrical body of said base;
• and
• a fastener oriented along a centerline of said cylindrical body, said fastener passing through said central recess and through said cylindrical extension, and securing said adapter plate to said base in a manner allowing rotation relative to said base with said cylindrical extension located within said central recess.