The reason I list 'Lan Guifei's Corpse' as a possible is that the cast list includes both Ziyuan Xu (who plays Chan in these films) and Meijun Gu (who plays Chan's daughter Meina in the early part of this series). It was also made in 1937, which is just one year before 'The Pearl Shirt' in (1938). The screenwriter/director for both films was Xinfu Xu and it was the same photographer and production company. Also, the film is described on one website as some sort of mystery film.
All of these points of similarity seem to suggest that 'Lan Guifei's Corpse' was perhaps a Chan film, but there is no confirmation of this to be found. It could also be a mystery film that starred these two individuals and that inspired Xinfu Xu to have these two actors play Charlie Chan and his daughter in a series of Chan films.
The fact that Charlie Chan and his daughter arrive in China from overseas at the start of 'The Pearl Shirt' gives me the impression that perhaps this is the first Charlie Chan film in the series of Chinese-made films and that this and not 'Lan Guifei's Corpse' is the film that is perhaps also known as 'Charlie Chan in the Homeland'.
