What Could Have Been: In one interview, Alan Moore said that he originally considered having Irene Adler lead the team, but ultimately settled on Mina Harker instead because he worried that Adler was too obscure.
Roger Moore was offered a cameo as Campion Bond, a part that was ultimately cut from the script, and would've been the first time two actors to have played James Bond shared the screen.
The ending cuts to Quatermain's hand coming out of the dirt and grabbing his rifle. A Call Back to what he said earlier in the film, "Africa will never let me die." But that wasn't used because they want to leave it ambiguous. At the least though it left the film open-ended rather then set up for a sequel that'll never come.