Old refrigerator drawer was getting thrown out at work (I don't know the backstory), so I cleaned it up and designed a rail system for mounting it under my 3D printer workbench to hold my 3D printing tools. If you look in the pictures, the bench has a 3/4" plywood sheet on top of a 2x4 frame; the frames screw into the bottom of the plywood and the side of one of the 2x4s of the frame. Yes, this is a very niche design.

I color coded the design for you guys if you want to put it together. Here's what you need for each side (mirror everything for the right-side rail):
Yellow - Front Bracket (x1)
White - Front Lock (x1)
Green - Front Rail (x1)
Black - Back Rail (x1)
Red - Back Bracket (x2)
"#4 screws to screw it in (minimum x12)

Instructions

Everything should be a friction fit, so expect to clean up the edges where things have to fit together. I had to use some force even after sanding down all the edges and using my scraper tool to clean up the inside corners of the dovetails joints.

After fitting everything together, line up one of the rails with the drawer in the closed position, making enough room so that the drawer is not sticking out past the 2x4. You can then remove the drawer and mark off with a pencil where you want the rail brackets to sit. Screw in one side all the way.

Then you can attach the other rail to the drawer and slide it in place, once again in the closed position, to mark off where the other brackets will mount. Remove the drawer and screw the second rail into place. You should now be able to slide the drawer all the way in.

You can now place the clip in place by fitting it over the top of the front rail where there is a space, and, using some force, pop the clip into the bottom, being careful not to break the rail. This clip keeps the drawer from tipping out of the rail system when the drawer is completely open. I only needed to use one of them.

For that ~1 person that needs this exact design...here you go.