Due to the complete lack of available plot details, character information, or thematic summaries for 'The Twins, 1979', it is not possible to assess the film's portrayal of LGBTQ+ characters or themes. Therefore, no determination can be made regarding its net impact.

There is insufficient information available regarding the film 'The Twins, 1979' to assess its portrayal of transsexual characters or themes. Publicly accessible plot summaries and cast details do not mention any relevant elements, making it impossible to determine the net impact.

The movie does not contain any action or adventure elements.

The provided details for "The Twins, 1979" do not include information about any source material, prior adaptations, or historical figures. Without a baseline for character genders established before this film, it is not possible to determine if any gender swaps occurred.

There is no information provided regarding source material or prior character portrayals for 'The Twins (1979),' making it impossible to establish a baseline for character races and thus determine if a race swap occurred.