re: Just a thought
TH LM ascent modulw would be a very poor basis for a pressurised bus. The skin of that vehicle was so thin you could have poked a biro through it. This photo shows that the original flat panels were crumpled like tinfoil after the stress of launch - you wouldn't want to bump across the surface of the moon in an egg-crate.
A whole new, stronger, design is needed,IMHO.