The corncob comes about from the dropship positioning which was not really fully explained (or shown in the 2750) book, and the 3057 abomination had them just landing all over the ship which would have played unholy hell with any internal layout.
actually the 3057 art appears to have the docking collars arranged radially, in rings down the length of the ship. there are 4 rings, so the pattern wouldn't be as simple as 5 per ring (you'd probably have to do 7,6,6,6), the implication appears to have been that the docking collars are staggered in layout, probably to simplify docking some when the ship is already loaded with more than a few dropships. a fully loaded Potemkin using such a layout would actually look rather like a corncob.
the IWM miniature went with this interpretation:
personally i rather like the 3057 art.. it looks more logical for its role, and isn't going to be be confused for.. well, any other TRO2750 SLDF warship. seriously, this thing in TRo2750 looks way too much like the TRO2750 Cameron, or an upsidedown TRO2750 congress. and or a Black Lion with the "fins" at a different angle.
unlike most of the TRo3057 art, this thing feels Btechy.. its basically a massive jumpship.. a long cylinder that huals rings of dropships. only this one is massive and has an actual transit drive.
as far as the bow indent goes.. personally i'd make that where the main cargo hatches and smallcraft bays are located. babylon 5 style, perhaps drawing on the old
Cruiser Class Cruiser as the in universe inspiration.