4) Heteromorph ammonite Hamites, which grew in a paperclip shape
Don't know much about the curly ammonites, but for the straight fragment, I can tell you for certain it isn't Hamites. It appears to have tubercles, and basically none of the Hamitidae have tubercles (one species, Metahamites might do, but that depends if you include in the Hamitidae).
There are three general of heteromorph that you find in the Gault Clay that have tubercles and paperclip shape: Protanisoceras (essentially only at the base, Beds 1 and 2 I think, but maybe a tiny bit higher), and then two that are found much higher up (bed 10 upwards), Anisoceras and Idiohamites.
All three are members of the Anisoceratidae. Protanisoceras is basically a Upper Aprian, Lower Albian genus, whereas Idiohamites and Anisoceras are Upper Albian, Lower Cenomanian genera. None of them occur commonly (if at all) in the middle part of the Albian in the UK, though presumably there are species that swam about in Middle Albian times since Protanisoceras is ancestral to Anisoceras and Idiohamites.
The best way to tell them apart quickly is size. Protanisoceras tend to be small, the longest dimension of the paperclip being something of the order of 10 to 20 cm. Idiohamites tend to be about twice that size, and Anisoceras even larger (some specimens exceeding 60 cm in length). Translating that into thickness, Protanisoceras is about the girth of your little finger, Idiohamites something between your forefinger and your thumb, and Anisoceras anything up to the thickness (and oval shape) of a hockey stick.
Spines and ribs are useful too. In almost all cases the spines themselves have snapped off or been eroded so what you have are the spine bases, known as tubercles, looking like round knobs. Anyway, Protanisoceras spines are on the edges of the ribs, sometimes one pair, sometimes two. The ribs may be flattened a bit between the spines as well, giving this ammonite a distinctive polygonal whorl section. Anisoceras have one or more commonly two pairs of spines, but instead of simple or flattened ribs the rib loop into ovals between the two ventral spines (the ones on the "back" of the fossil rather than the sides). This is called the "loop and button" morphology, and once you see it, you'll see the resemblance. Finally, Idiohamites only ever have a single pair of spines and the ribs are not flattened or looped (though two or three ribs may "bunch" at a spine base, they don't form loops or ovals). In all cases the spines may weaken on the later part of the shell. In Anisoceras and Idiohamites especially, the rib bearing the spines become extra thick compared to the 2-4 ribs in between them that lack spines. You do see this in Protanisoceras as well, just not so profoundly.
Looking at the picture, I think what you have is a species of Idiohamites. There are three species from the Gault that are most commonly seen, of which Idiohamites spiniger is the most common. It has 2-3 plain ribs between the thick ones bearing the spines. Idiohamites subspiniger is a doubtfully distinct species with coarser ornamentation. The species that is definitely different is Idiohamites ellipticoides that has very weak plain ribs between the spiny ones, and, as the name suggests, a strongly elliptical whorl section.
Cheers,
Neale