With the assistance of my wife, we slid the forward fuselage into place to join the rear fuselage. I took the HBH advice and fit the sides of the cabin on top of the gussets rather than between the gussets and rear skin. It does indeed seem to be a better fit and won't present a raised edge to the wind. Cleco'd the joints and supported the front.
As noted previously, the top edge of the cabin frame on the pilot side was mis-cut by me a tad short with not a lot of room from the 1st pilot hole to the end of the frame. I had deferred enlarging the hole until now. I decided to locate that 1st hole forward just a couple of mm so that the outside of the hole when enlarged to #20 would match the edge of the pilot hole and I would not be any closer to the end of the frame. I used a scrap of longeron from the rear fuselage and made a template and drilled the relocated hole. Not the finest finished hole, but I'm calling it good.
I also way underestimated how many additional A5 rivets I would need, so I used up what I had left and placed another order for more. So the joining of the fuselage is incomplete at the moment.