Over the course of several days, I gradually applied several thick layers of an ultra-strong two-component epoxy adhesive to all sides and gaps and let it dry through overnight. I had thoroughly cleaned the frame and main body beforehand and at the beginning I used clamps to hold the parts in place while gluing.

I didn't photograph every step because it basically always looked like above. After mixing, the glue had a high viscosity, but was still liquid enough to run down the sides. Therefore, within the first hour of application, I periodically checked to see if the glue was still in the desired places and removed glue drops.

After the glue was applied to all sides and dried, I first roughly filed off the excess glue by hand and then sanded the sides into shape. I used different types of sandpaper, first dry sandpaper (grits from coarse 150 to fine 800) and later wet sandpaper with finer grit sizes. Then I sprayed on a first coat of a filler/primer mix, let it dry and sanded it down again.

Of course, there were still some blemishes like tiny air bubbles, so I repeated these steps several times...

Sanding the long sides was quite easy. More difficult were the recessed areas, the edges and especially the front. Here I had to touch up several times because the glued-in ABS profile remained visible for a long time. After applying a new coat of filler, it was always quite easy to see where touch-ups were needed:

After way too many hours of sanding, I was finally satisfied with the look of the main shell (but not quite finished yet). There were still a few minor blemishes, but all in all, the glue joints were no longer visible, and I think I also managed to make it look like it was cast in one piece.