  We observe long-range $^{85}$Rb and $^{87}$Rb (24$D$+5$S_{1/2}$) Rydberg
molecules for eight different spin couplings, with binding energies up to
440~MHz and sub-percent relative uncertainty. Isotopic effects of the molecular
binding energies arise from the different masses and nuclear spins. Because the
vibrational states involve different spin configurations and cover a wide range
of internuclear separations, the states have different dependencies on the
$s$-wave and $p$-wave scattering phase shifts for singlet and triplet
scattering. Fitting the spectroscopic data, we comprehensively determine all
four scattering length functions over the relevant energy range as well as the
zero-energy scattering lengths of the two $s$-wave channels. Our unusually high
temperature and low density (180 $\mu$K, 1 $\times$ 10$^{11}$ cm$^{-3}$)
suggest that the molecule excitation occurs through photoassisted collisions.
