Recetly I was able to add a couple hours of exposure time to an image I started a couple weeks earlier. I took some doing to line up the frames but was finally able to match the star pattern well enough so that the outer edges of the image did not show to much layering. After cropping out a small amount the final Image is presented here.
This is 4 hours of exposure from to different dark sites, one very dark with no moon and the other not so dark and I had a portion moon for 2 of the 3 hours of exposure.
I used a starlight express M25C and a FSQ 106 mounted on a atlas mount and guided using a borg 50 mm