That deleted scene has been the source of conjecture for at least ten years, I believe. Hawaii Steve has a 16mm print of "The Black Camel" that has been similarly altered. My opinion is that his shortened copy, as well as the version of "The Shanghai Chest" that you mention, is more the result of shortening the running time in order to accommodate television airing in a time slot than one of censorship.
However, we do see a censorship of ideas (and, in fact, a censorship and a re-writing of the past!) around us today that is growing at an alarming rate, sadly and, ultimately, tragically. Truth is the ultimate victim. This has surfaced against Charlie Chan in recent times through the organized (and well-funded) work of various special interest groups. The best cure for this growing societal malady, I feel, is to remain ever vigilant, educate ourselves as to the FACTS (over emotion), and to let our voices be heard.
Sorry it took so long to reply. "Shanghai Chest" is the only Chan film I have that I noticed such a cut. My DVD versions of "The Red Dragon" and "The Chinese Cat" correspond with my old VHS copies.
The first VHS copy of "The Black Camel" that I bought years ago on eBay omitted the crystal ball scene between Tarnevarro and Sheila, which I don't understand since it is important to the rest of the storyline. I think the DVD versions now being sold have the scene intact.
