In my old 13-inch the galaxy itself appeared fairly faint, elongated 5:2 SW-NE, with a low almost even surface brightness. The unusually bright HII region is at the SW end of the galaxy (2' from the center) and appeared as a "fuzzy" 12th magnitude star. Although very small it seemed elongated SW-NE and similar to a poorly resolved double star. An OIII filter will verify this is an emission object.
If you've never tracked down an Abell planetary, this one is a great introduction. The field is a snap to locate because Abell 33 has a mag 7.2 star (SAO 137026) embedded in the SW end! With my old 13-inch f/4.5, the planetary spanned 4' and had a brighter rim using an OIII filter, giving a partially annular appearance. Although the planetary has a low surface brightness and was missed by the visual surveys of the 18th and 19th centuries, it was visible with direct vision using the OIII filter and is a lovely sight in larger scopes.
Still looking for a more extreme challenge? Shakhbazian 49 is a very challenging compact group of compact galaxies situated just 20' NE of the NGC 3158 cluster. This is a marginal object in my 17.5-inch. At 220x an extremely faint knot, perhaps 15", was glimpsed several times with averted vision, using a finder chart. At 280x, there was a strong impression of two very close 16th+ magnitude stellar objects, though I couldn't view both objects simultaneously. Perhaps a 20 to 25-inch scope would be able to cleanly resolve individual members.
A remarkable chain of galaxies, HCG 56 is located a mere 7' south of the bright barred spiral NGC 3718. Photographs reveal five members with the central trio appearing as an interconnected chain chain. However, visually resolving the members should challenge even hard-core deep-sky observers. At 100x, this compact group merged into a faint elongated glow just 1' long, strung out roughly east-west with a 3-1 ratio. Increasing the magnification to 220x resolved a pair of knots: HCG 56b and HCG 56c. HCG 56a is the largest member of the group, but this low-surface-brightness edge-on spiral required careful viewing. Observers using Lord Rosse's 72-inch reflector examined the field of NGC 3718 four times between 1852 and 1868 and missed this galaxy chain, so just detecting this group should be considered an accomplishment.
Markarian 205 is quasar-like object that has been steeped in controversy over the years due to its possible connection with the disturbed galaxy NGC 4319. Since the early 1970's Halton Arp has argued that deep photographs show a "bridge" of luminous material leading back to the main galaxy - in apparent contradiction to the standard intrepretation of redshift as a distance indicator. I took another look last July at the Sierra Buttes, in the Gold Lakes Basin region of the California Sierras. Markarian 205 was visible as a mag 14.5-15 "star" less than 1' south of N4319. Although easily visible with averted vision, this object was fainter than recalled from earlier observations.