After giving it some thought during the week I decided I would take the incorrectly positioned control tunnel side out and move it forward of the baggage upright (instead of behind where it is supposed to go) and see if that would be enough to correct the gap.
Unriveting went surprisingly well using just a #30 drill bit to take off the heads and then some pliers to pull out the tails, and the tunnel side was soon removed.
I re-rivted the back flange on the front of the upright and redrilled holes in the bottom of the side.
After riveting you can see that there is now hardly any gap at all at the front, things should line up nicely.
I didn’t know if I would need to order a new control tunnel top but it fit pretty good now that the tunnel side was corrected. I had to redrill some holes on the pilot side but I think that this will work out.
So at this point I think the rear fuselage is complete. I deburred and primed the riveting surfaces for the forward fuselage join and hopefully tomorrow someone will come to the hangar and help me put the two halves back together.