There's an interesting tidbit regarding MCG +10-16-024. It was missed by William and John Herschel (not surprising), but it was discovered visually in March 1856 with Lord Rosse's 72-inch Leviathan. While observing NGC 3445, the assistant R.J. Mitchell remarked that "the nebulosity outside this dark curve runs up perhaps to a streak [MCG +10-16-024] south-following [SE] which is very faint, but of the existence of which I have no doubt."

Mitchell returned to the galaxy in early April 1858 and confirmed "a very faint, small patch of nebulosity south-following [of NGC 3445]." The 1856 observation was included in Lord Rosse's 1861 observations of nebulae and clusters, but for some reason John Herschel decided to ignore it when he compiled his General Catalogue (GC) in 1864. Why wasn't it included? I'm guessing because Mitchell gave no offsets (other than southeast) for the companion 'nebula', Herschel didn't even have a rough position to go by.

The bottom line is that Dreyer skipped MCG +10-16-024 when he put together the NGC in the late 1880s, although the galaxy actually deserves a NGC designation!