The future neutrino research program will require improved precision. A major source of uncertainty is the interaction of neutrinos with nuclei that serve as targets for such experiments. Broadly speaking, this interaction often depends, e.g., for Charge-Current Quasi-Elastic (CCQE) scattering, on the combination of ``nucleon physics" expressed by form factors and ``nuclear physics" expressed by a nuclear model. It is important to get a good handle on both. This talk presents a fully analytic implementation of the Correlated Fermi Gas (CFG) model for CCQE electron-nuclei and neutrino-nuclei scattering. The implementation is used to compare separately form factors and nuclear model effects for both electron-carbon and neutrino-carbon scattering data.