As of 0.4.5e, as far as I've found, it's impossible to have both the 'Penis (stage 6)' and the 'Swimmer Legs' transformations, as both chances to receive the legs transformation are also mutually exclusive Penis Reduction transformation points (Mermaid Caves and the Bath House). This leaves you either with either Penis (Stage 5) /w Legs and the Androgenous state or Penis (Stage 6) /wo Legs and the Manish Girl state.