By way of comparison with known properties of bulges in spiral galaxies, the bulge radius is actually larger than found by studies of bulge-to-disc scale length correlation by roughly a factor of 2 (Courteau et al. 1996). However, NGC 6503’s bulge also displays certain characteristics typical of nuclear clusters, even though its size exceeds typical nuclear clus- ters by about two orders of magnitude (Walcher et al. 2005). Unlike normal bulges, nuclear clusters are often offset from the dynamical centre of the galaxy (Matthews & Gallagher 2002). NGC 6503’s bulge displays this phenomenon – the photometric centre is offset by ∼ 100 pc. Nuclear bulges also have very small mass, typically ≲ 5 × 10 $^{7}$M ⊙ (Walcher et al. 2005); the mass of NGC 6503’s bulge is only slightly larger. Thus, NGC 6503 has a surpris- ingly low density bulge. Furthermore, Walcher et al. (2005) find that their nuclear clusters’ velocity dispersions are similar to that found in NGC 6503. Their nuclear M/L$_{I}$ ratios are also consistent with the M/L$_{R}$ values we find ( § 6.4), in that we expect the M/L$_{I}$ values to be slightly lower than our M/L$_{R}$ values, which is precisely what occurs. Thus, NGC 6503’s bulge properties are consistent with both nuclear clusters and ordinary pseudobulges. The origin of nuclear bulges is unclear, but it is plausible that they are formed by secular evolution. Walcher et al. (2006) find that repeated episodes of gas infall may contribute to nuclear cluster star formation, which is required to maintain their high luminosity. In the case of scenario E, bar formation may induce gas inflow that would generate a nuclear cluster that could in turn generate the σ − drop. The most likely hypothesis is that of a pseudobulge that has a luminous nuclear cluster at the centre dominating the observed light. The halo cusp γ is well-constrained, as Fig. 17 attests. All runs suggest that the halo is cuspy, a result that is therefore quite robust. In the case of runs K and KL, we find γ = 1 . 2 and γ = 0 . 9, respectively. For scenario KG, we find that γ is close to 1 and therefore consistent with a NFW profile; this cusp is flatter than for the equivalent scenario that fits the stellar rotation curve. Meanwhile, scenario E suggest a very strongly cusped halo with γ = 1 . 4. Thus, the derived cusp value depends on the density profile of the disc and the choice of rotation curve. Unsurprisingly, a stronger cusp is required to compensate for the lack of central mass in an inner truncated disc. In addition, we find a statistically significant difference in cusp values depending on which rotation curve is fit, but both cases are consistent with or cuspier than cosmological simulations. If the assumption that gas traces the circular velocity is erroneous, then the slope of the circular velocity curve must be steeper at the centre (as seen in Fig. 5), and hence the derived cusp value will be larger. Thus, modelling asymmetric drift correctly is essential to obtaining the correct halo density 21 6.3. Halo cusps