4" Peglock Bracket for any type of Pegboard.  Designed around the dimensions of a standard 1" x 4" board (which means the actual dimensions are slightly smaller).  Make your shelf as long as you need, just print addtional brackets.

You should be able to use any of the below peglock mounting systems.

Pegboard: Sy's Peglock Board Attachment Peg - Free 3D Print Model - MakerWorld

Skadis: Sy's Peglock - Ikea Skadis Remix - Free 3D Print Model - MakerWorld

Wall Control Pegboard: Peglock For Wall Control - Free 3D Print Model - MakerWorld

Square hole Pegboard: Sy's Peglock - Square Hole Pegboard - 5mm Holes - Free 3D Print Model - MakerWorld

Din Rail: Sy's Peglock DIN Rail Attachment, Stronger - Free 3D Print Model - MakerWorld

Rubbermaid Fasttrack Rail: Fasttrack adapter for Sy's Peglock system - Free 3D Print Model - MakerWorld

Rubbermaid Fasttrack shelf vertical rail (will also likely need something custom to handle the 3" dual peg spacing for this print): Peglock adapter for rubbermaid shelf railing - Free 3D Print Model - MakerWorld