Purchase, Print and Prepare the Parts.
I purchased one 36" by .125" weld rod (any ferrous rod will work fine) and six 3mm diameter by 2mm thick neodymium disk magnets from my local hobby shop. I created the two locking pins by cutting two 28mm lengths from the weld rod using a hand held motor tool, then polished the cut ends again using a hand held motor tool to remove all burrs.
I printed two of "End.stl", one each of the remaining parts, at .15mm layer height with 20% infill.
Prior to assembly, test fit and trim, file, sand, etc. all parts as necessary for smooth movement of moving surfaces, and tight fit for non moving surfaces. Depending on the colors you chose, your printer model and your printer settings, more or less trimming, filing and/or sanding may be required. Carefully file all edges that contacted the build plate, especially in and around the dovetail joints, to make absolutely sure that all build plate "ooze" is removed and that all edges are smooth. I used small jewelers files and plenty of patience to perform this step.
Assemble the Sides.
Stack three of the neodymium magnets together, place them in the non-through hole in "Side Left.stl", then secure in place with thick cyanoacrylate glue.
Slide one of the pins into the remaining hole (the through hole) in the left side.
Test the assembly to make sure the pin will disengage from the magnets when the pin end of the side is sharply struck on a firm surface.
Repeat this process with the remaining side, "Side Right.stl".
Assemble the Box.
Press one "End.stl" onto one of the side assemblies as shown, making sure the dovetail pins and tails are tight.
Press the remaining side assembly on the opposite end of "End.stl" as shown, again making sure the dovetail pins and tails are tight.
Press the remaining "End.stl" onto the assembly as shown.
Place "Top.stl" on the assembly as shown, then test the locking mechanism.
After testing, remove the top, press the side / end assembly into "Base.stl" as shown, glue in place with thick cyanoacrylate glue, then replace the top.
Slide "Ribbon 2.stl" onto the box as shown, followed by "Ribbon 1.stl", and align the half lap joints as shown.
That is how I printed and assembled "Simple Secret Box V: Gift Box Edition".
Hope you enjoy it!