Nice package.
I made one similar where the marlinespike and the knife were parallel. The sheath was leather, however.
First I made an oversize sheath blank, with a belt loop top. I stitched the keeper strap and the loop to the back next.Then I made a 1/4" wide welt the thickness and taper of the marlinespike, rolled the sheath, and cemented it in place inside the roll to make a pocket for the spike. I then set the knife between the layers and marked the cut for the sheath edge (allowing for the outside welt). I made the welt and cemented it in place (I use leather weld). After sanding the edge to size,I stitched the outside welt and the spike welt.The spike lay right along the knife spin, separated by the 1/4" welt.
Stacy