Modular sight system, back plate receptacle and interchangeable devices for guns

A modular rear sight system and back plate receptacle for guns having a slide with a gun rear sight and rear back plate section for receiving a cover plate, comprising:

• a back plate receptacle, said back plate receptacle having a mounting base and an attachment receptor;
• said mounting base for fitted engagement with said slide rear back plate section;
• said mounting base having a protruding flange about its periphery for fitted engagement within said grooves of said rear back plate section;
• said attachment receptor for receiving interchangeable sight attachments;
• said attachment receptor having a central recess and an alignment slot for receiving said interchangeable attachments in fitted engagement, said interchangeable attachments being inserted and secured therein;
• interchangeable attachments for fitted engagement within said attachment receptor;
• said interchangeable attachments comprising a generally rectangular vertical sight member, said vertical sight member being secured within said central recess and alignment slot;
• and
• said vertical sight member being complementary to said gun rear sight and aligned therewith.