Fuselage: Forward Mid Fuselage Bulkheads.

There are a few steps in this section that benefit from a deliberate approach before executing:  Check, double check, check again.

The bearing bracket assemblies.  There are four of these, two pairs of each.  Only one side on each pair is countersunk.  And it's the side that doesn't hold the bearing.  Additionally, only the outboard sides get #19 countersunk for #8 screws (so one -L and one -R part).  These assemblies are an attach point for the control columns (see page 29-05).

Update 27-Nov-14:  As I was riveting the mid fuse bulkhead parts together today, I came to realize that I should not have countersunk the outboard AD4 holes on these assemblies (left image).  Indeed, the plans are clear on this.  Slashes (right image) shows the AD4 holes that should not be countersunk.  Easy ~$15 of replacement parts to fix.

Similar deal for the bulkhead bars.  These will capture and bolt on to the rear spar of the wing (remember that "critical hole" you reamed back on page 15-04?).  These can use some minor straightening.  I suggest this approach, used to straighten the horizontal attach bars.

It helps to have a countersink extension (needed in Section 28 anyway) to countersink the top hole in each of the F-01441-L/R bearing bracket braces (see page 25-05), as the flange impedes cage access.  I used a pilotless, zero-flute countersink, which is potentially disastrous if not done carefully.  By the way, if you're having trouble locating F-14143 (bearing bracket angle), it's in bag 3062.

Be sure you countersink the correct holes on the F-01404D-L/R side angles.  I originally marked off the wrong set of holes and caught the oversight on the "measure twice, cut once" step.

Here are the flush rivets holes in the bulkhead top and bottom flanges after countersinking and spot priming.  You'll want to grab a 0.311" reamer (Avery's or McMaster-Carr) for a few holes on these and on the F-01405 bulkhead assembly.

All parts are prepped for Section 25.  Next step is priming and assembly.  However, I will prep some parts in the next section too so I can more efficiently use the time spent in overhead setting up the priming accoutrements.