@jmstine - thanks for more info on Jimmie Dale. I hadn't heard of him a week ago, so it's all news to me. One of the tricky things about identifying predecessor characters, there's often an even earlier examples. For instance, the Scarlet Pimpernel left a calling card (a note with a picture of a flower - a pimpernel - drawn in scarlet ink). AJ Raffles is an amateur but skilled cracksman. Not a 100% match with Jimmie Gray, but you can trace things back. But that's the advantage of a community, we can share information and ideas.
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The Shadow 3 (series 1)