I have made custom fitted inserts for carrying cases before (see here for examples) using laminated cardboard to make a block, and cutting out an outline of the contents. In those cases, there was a lot more space, but with the pistol and two sights in the cigar case, there wasn't much space left over; cutting a solid block of cardboard would leave little left behind, and would probably be too flimsy. I decided to stick with the cardboard, which is free and easy to work with, but use more of an "English fit", or partitioned style. This would let me build up the shapes, rather than cutting them out, and as long as the partitions are supported at each end, would produce a sturdy insert.
hot glue gun
empty cigar box or similar container of a suitable size
felt (the thick stuff sold by the yard, not the thin stuff sold in small sheets; you want the fabric to be able to stretch)
Ribbon to use as handles
Tissue or other paper to cover exposed cardboard
Elastic band, needle and thread to make hold-down straps
Step 1: Deciding on the Layout
If the items don't lay flat, that's OK, because you can build up underneath the shallow portions to raise them up so the item sits level.
Step 2: Buiding the Base
Once the box is made, the items can be placed inside and traced to provide a guide to use when we start to add the partitions. You'll need to keep the items handy while you add the partitions, so you can keep checking the fit as you go.
Step 3: Adding the Partitions
Now we start to cut and add the partitions. The partitions do not need to be as high as the sides, and in fact it is easier to cover the partitions if they are lower. They do need to come about halfway up the sides of the items to provide a secure hold, so keep that in mind when you choose the height. I chose one inch, since that is how wide my ruler is, and that allowed me to use the ruler as a cutting guide to get straight, consistent partitions.
Whenever you join two partitions at an angle, make sure to use a fillet of hot glue to provide strength.
Step 4: Finish Up Partitions
In this case, the back of the grip left a fairly large open area. Rather than try to fill this with cardboard (which was done by the laser sight) a couple of pieces of cardboard were put at the widest area of the curve to provide strength, and the void was filled with paper. The paper was crumpled up and stuffed firmly into each section.
Leave a small amount of space around each item, since we are going to be covering this with felt. The felt will provide padding and take up the extra space, and will hide the cardboard and leave you with an attractive surface.
Step 5: Add Felt
After you have the felt fitted, carefully flip everything over and pull the cardboard up off the felt. Spray the felt and cardboard with spray glue, and then quickly slide the cardboard back in place, and flip everything over. You'll need to work the felt back down into the partitions quickly, while the glue is still tacky. Work from the middle out, smoothing out the wrinkles and pushing the felt down onto the tops and sides of the partitions to get a smooth surface.
When the felt is as smooth as you can get it, use the hot glue gun to run a bead along the outer top of the insert, a few inches at a time. Press the felt firmly down onto the glue. If you have a wrinkle along the edge, just pinch it flat and glue down the sides.
Once the glue has set around the outside, get a good sharp pair of scissors, and cut the felt as close to the edge as possible, all the way around. Put a bit of glue inside each wrinkle, and push it down along the edge, then use a razor knife to trim any felt and/or glue that goes past the edge.
When you're done, the insert should fit snugly into the cigar box. A loop of ribbon wrapped around the insert and sticking up on the sides will allow you to slide it out if needed, though that is optional on the bottom layer.
Step 6: Making the Shelf
easily. Like the bottom insert, the sides are assembled first, and then the bottom panel is placed inside. Since the laser sight and red dot sight sit up above the edges of the bottom, I placed the shelf sides into place on top of the bottom, with all items present, then carefully set the shelf's bottom into place, and glued it in. This placed the bottom part of the way up the sides, and left a space to glue in a rectangle of felt for padding.
Since the sides are visible, I covered the shelf in a layer of green tissue paper, using spray glue and smoothing the wrinkles flat and trimming the excess. The picture shows the bottom side, which has loops of ribbon hot-glued in place, with the felt glued on afterwards to cover the ends. The top of the shelf is also lined with felt.
Step 7: Add Elastic Strip for Holding Assorted Items in Place
It's fairly easy to stitch through the cardboard with a normal needle and thread. I would recommend having fabric on each side of the cardboard when sewing through it, to prevent the thread from cutting through the cardboard and coming loose. Be careful to keep the needle perpendicular to the surface when you push it in, because even a few degrees of angle will result in a noticeable deviation from the line when the needle exits the far side.