I used several thicknesses of Baltic Birch ply to make the box, because I had a bunch of partial sheets left over from a large project. The box sides are 1/2". The top and bottom are 1/4". The manual holder and some of the supports are 1/8". All could be made from solid wood, if that's all you have. Since plywood is very stable, I just clued the top and bottom onto the sides with no provision for dimensional changes due to humidity level variations. If you use solid wood, slot the sides and fit the top and bottom into the slots to allow for expansion and contraction.
My CRB7 is a Mark II, so when they came out with the MHLF option and the Mark III, I had already made the box. The only difference between the Mark II and the Mark III are two additional holes that were added to the base to allow attachment of the MHLF. I was able to modify my Mark II very easily to make it a Mark III. The difficult part was figuring out how to make the MHLF fit into the already built box, but I succeeded. I would have done it differently if I had waited and not built the box until the MHLF became available. I think I spent almost as much time figuring out how to get the MHLF into the box with a minimum of modification, but everything fits now, but I probably should have just started over and made a whole new box.
I like to make boxes for any of my tools that have many small parts, to keep everything together. This box actually has 4 layers of pieces in it. The bottom most layer holds the rods in the back and the optional guide rails toward the back, separated from each other
by a strip of Baltic Birch. The next level holds the lower piece of the jig that is used for edge trimming. The third level holds the jig itself and the right end has a block with holes to hold the handle, the centering pins, the guide foot that stabilizes the jig when edging, a small pill container for the attachment screws and bolts, the edge trimming bearing, etc. and the fourth level is in the lid holding the manuals and paper work associated with the jig. Level 3A is the newly created level for the MHLF option. I have to remove the guides from the MHLF and put them in level 1 to get the MHLF into the box, but doing it saves me from having to make a whole new box. I never took a picture of the addition of the MHLF into the box yet, so I'll have to take a few and post them here, but it may be several days before I'll get the time to do it. I have other commitments (life getting in the way of shop time).
Central North Carolina