Which craft do I model: Apollo 8, 9, 11, 13, or 15? Not so trivial a decision, if I really want to have a reasonably accurate model.

The S-IC stages had retro rockets. All of these missions used 8, except for Apollo 15, which used only 4.

Some of the S-II stages used ullage rockets: 4 on all of these except 15, none on 15.

If I model Apollo 15, how much will I need to muck with the wraps (“2nd Stage Aft Skirt and Interstage” wrap for the ullage rockets, “Thrust Structure” wrap for the retros)? Can I even make these mods, or is it 4 ullage rockets and 8 retros, period?