papers in this series. In Paper III, we have measured the structure and kinematics of the [ <span style="font-variant:small-caps;">HI</span> ]{}in these galaxies, using modelling procedures that allow for the correction of self-absorption in the [ <span style="font-variant:small-caps;">HI</span> ]{}for assumed spin temperatures. The stellar discs were modelled in Paper IV. Based on the quality of the results from Papers III and IV, we have decided to model five out of the original eight galaxies in our sample. These are IC5249, ESO115-G021, ESO138-G014, ESO274-G001 and UGC7321. All five galaxies are late-type Sd, with self-absorption corrected [ <span style="font-variant:small-caps;">HI</span> ]{}masses between $4.1\!\pm\!0.1\!\times\!10^8$ and $7.8\!\pm\!0.8\!\times10^9$M$_\odot$ (Table 1 in Paper III). The distances vary greatly between these galaxies. ESO274-G001 is only 3.0Mpc away, while the distance to IC5249 is estimated at 32.1Mpc.

In Paper III, we successfully measured the velocity dispersion of the [ <span style="font-variant:small-caps;">HI</span> ]{}as function of radius in ESO274-G001 and UGC7321. In ESO115-G021, the velocity dispersion appeared to increase with radius from about 7 [[km s$^{-1}$]{}]{}in the inner parts to 12-14 [[km s$^{-1}$]{}]{}at the outer measured point. As we are skeptical of this result, we will adopt a constant velocity dispersion of 10km/s for this galaxy. We also adopt this constant velocity 