Film/Book differences (spoilers)
As I'm more familiar with the Al Adamson film version, I was quite surprised that Marc Olden's source novel features a scene set in Croydon. I guess Adamson wasn't able to rustle up any stock footage of Croydon for the movie, it's somewhat disappointing though that Adamson chose to turn the character of Molay into the bad guy's pet vulture, whereas in the novel he is the bad guy's pet werewolf!
Here's a few more ways that the film and the book differ:
-Toki is kidnapped in Hong Kong in the film, whereas in the book that happens in Saigon.
-In the film she is kidnapped to blackmail her father for money, in the book she is kidnapped to dissuade her husband from testifying in Washington against corruption in Saigon.
-In the book Chavez is trying to avenge the death of his brother Benito, who was killed by the Black Samurai a year earlier.
-Bone is depicted as black and asexual in the film, but in the book is an albino chickenhawk.
-Synne has silver hair in the book, and is killed by Chavez during rough sex, whereas the film keeps her alive for much longer.
-The Black Samurai's run in with Reinhardt and the Leopard men takes place right at the start of the book, but the film moves that to much later on.
-The film eliminates the crucial character of William Baron Clarke, a wealthy former president who sends the Robert Sand/Black Samurai off on various missions. Clarke is essentially the M to the Black Samurai's Bond, but with added racial tension to their relationship "Boss man, thought Sand. Until they take him away, that's what he'll always be. Boss man". He's replaced in the film by the succession of white CIA agents who are depicted as being far more subservient to the Black Samurai.
Olden's book is also incredibly rude about dwarfs ("he looks like hammered shit"), the french ("Garlic. The French probably poured it on cornflakes") and overweight women ("the last thing the black samurai wanted was to be locked in a smelly gas station with a fat french lady who had a mustache"). I suppose it's up for debate whether the loss of that mean spirited attitude works for or against the movie. The jet pack stuff is unique to the Adamson film though, so if you want werewolf action go for the book, but if you want to see Jim Kelly fly the film is the only option.