I have heard of a few persons who claim to have watched at least one of these movies on TV in the early days of that medium. However, the only reliable way to determine if any of the four "lost" charlie chan films were ever shown on television would be through painstaking research of old channel listings in newspapers and 'TV Guide' magazine. To my knowledge, no one has approached this daunting task.
By the way, Gene, are you the one (your name rings a bell) who mentioned, sometime back, the showing of "Charlie Chan at the Race Track" at an El Segundo, CA theater the weekend of September 25? I plan to be there for a showing or two...