After careful study of the instructions and how the various components of the fighting compartment fit together, I decided to skip ahead to Step 10 and construct the rear portion first. Everything in the fighting compartment has to align within fairly tight space tolerances so it made sense to start at the back and work my way forward.
Step 10 assembles the rear hull portion out of three sections. The firewall section is molded with 2 of the brass shell base holders empty but the openings are molded solid. I corrected this with a drill bit and pin vise followed by careful sanding with a round needle file. I also installed the engine compartment intake inserts that are called for in Step 13 to insure everything played nice and to provide a little more structural rigidity to the top plate during the assembly.
I also assembled and installed the muffler to the rear plate. While not shown in the photo below, improved on the hollow exhaust pipe by deepening the opening and thinning out the sides of the pipe to be more in-scale with a combination of a drill bit and sharp #11 blade point.
I was going to complete the rest of the assemblies for the rear plate top as called for in Steps 11 and 14 but thought better of it after a test fit revealed that I was going to need to apply some pressure to get a good join with the fender on the right side of the hull. I did go ahead and install the hatch and PE grills and will add the other parts after the interior is painted, the gun installed, and the rear compartment glued in place.
I returned to Step 7 which deals with the upper right side panel of the fighting compartment. The kit provides a choice of what details to install here but for some reason doesn't call out the choice until Step 9, so if you aren't paying attention you can miss it. The choice is between two ready 15cm rounds or a large stowage box mounted between the angled support braces. Good interior photos of the Bison II don't exist and none survived the war so DML has done some speculation here of what might or might not have been there and either option is plausible in my opinion. I chose to go with the large stowage box.
I have to point out a potential pitfall at this stage and it deals with the angled support braces. They are shown in Step 7 attached directly to the side panel but the panel doesn't have any guide as to how they should be placed. If you go with the 2 ready round option that helps but the real locations are determined by the tab slots on the fender, so it's best if you install the braces to the fender and not to the panel as directed. Test fits along with the rear hull portion provide a guide as to how deep the large box should be mounted as it has to overhang the fender edge and not sit flush.
Important note: the rear hull portion IS NOT INSTALLED at this point, only dry-fit...it needs to remain loose to allow for the gun trail to be installed correctly in later steps.
That took me across the way to the left side of the compartment. There are a couple of things that have to be taken into consideration on this side. The first is that while the instructions call for 2 radio sets to be assembled in Step 9 (one receiver, one transmitter), the kit provides enough parts to assemble just 1. The missing parts are the mount frames RD4 and RD8, so I was able to fit only the transmitter because I had already assembled it before I discovered the parts shortage. I moved the transformer from behind the radio to next to it to fill the gap left by the missing 2nd unit and used a #76 finger drill to prep the radio and transformer to take wiring later on. The base of the transformer was glued down but both the radio and the actual transformer were dry fit only to test the layout and will be painted separately before final installation.
The other item for consideration are the 6 charge boxes, installed in two stacks of 3. These have raised lines molded on them top and bottom that make it difficult to "stack" them if not removed. They also add to the height of the stack slightly so removing them not only makes it easier to install them it also insures they sit the correct height under the panel overhang.
I added the other interior items that mount directly to the panel and used small strips of blue masking tape to test fit the panel and make sure everything sat correctly.