Now this is W. Reginald Bray, and he was known as The Human LETTER, which is your second link. The text explains that he was at that time the largest collectors of postal curios in the British Isles, and the first man to post himself as a human letter. It all started as a hobby in 1898 when he read in the Post Office Guide that the limits of articles which can be posted ran from a bee to an elephant, and decided to see what strange oddities he could manage to successfully send, including himself, his dog, and, well, you are directed to a fantastic website all about him, which includes one of these cards autographed by the man himself in 1938. and a whole page with all these cards autographed.
Because W.R. Bray was not just the post king, he was the autograph king too.
This set is listed in our original Churchman Cartophilic Reference Book No.10, issued in 1948, as item 80, issued in May 1938 - “50 “In Town Tonight”(titled series). Size 2 11/16” x 1 7/14” or 67 x 36 m/m. Numbered 1-50. Fronts printed by letterpress, 4-colour half-tone process. Backs in dark green, with descriptions. Printed by Mardon, Son and Hall.”
In Town Tonight was a really famous show, a bit like “What`s My Line”, full of interesting people with fascinating lives or hobbies. It lasted for half an hour and ran from 1933 to 1960, pretty much continuously. Someone has also mentioned that Dorothy or Charles Bagnall was on it, but I can only vaguely recall reading that Dorothy Bagnall was on Whats My Line.