Based on the information provided, the film "The Mysterious Bullet" does not appear to feature any identifiable LGBTQ+ characters or themes. Therefore, its net impact on LGBTQ+ portrayal is not applicable.

The 1955 British crime drama 'The Mysterious Bullet' does not include any discernible transsexual characters or themes. The film's narrative focuses on a murder investigation without any elements related to transgender identity, resulting in no portrayal to evaluate.

The movie does not contain any action or adventure elements.

No prior source material or established characters are provided for "The Mysterious Bullet" (1955). Therefore, it is not possible to identify any characters whose gender was changed from a previous canonical or historical depiction.

Research indicates that "The Mysterious Bullet" (1955) is a British crime drama adapting a novel with characters consistent with its setting and era. There is no evidence of any character canonically or historically established as one race being portrayed as a different race in the film.