Based on the provided input, there is no information available to assess the portrayal of LGBTQ+ characters or themes in 'Operation Grass Killer'. Consequently, the film's net impact on LGBTQ+ representation is not applicable.

Operation Grass Killer (1961) is an educational short film focused on lawn maintenance and weed control. It does not feature any identifiable transsexual characters or themes, as its narrative is entirely dedicated to agricultural instruction.

The movie does not contain any action or adventure elements.

There is no widely known source material or prior canon for "Operation Grass Killer" (1961). Without established characters from a previous work, the film cannot feature a gender swap as defined.

There is no widely recognized film titled "Operation Grass Killer" from 1961 by Herk Harvey with established source material or characters to assess for race swaps. Without prior canon, no character's race can be determined to have been changed.