Originally Posted by timnz
I can add a bit about the old World's Pro Championship.
The 1934 French Pro (Tilden beat Plaa in final) was originally called "World's Pro Championship" even though world champion Nüsslein did not paticipate.
In 1935 there also must have been a World pro Championship at Paris because I have an old clipping of 1936 with a hint to the 1935 event when Tilden won. No details known.
In August 1936 Nüsslein beat Tilden (SF) and Cochet (final) at Roland Garros in the world pro championship. No details known.
The 1937 Wembley event was called the world's pro indoor champ.
The 1939 French Pro was also labelled the world pro championship.
Thus we get a certain tradition of the World Pro...
I don't have the references to your indications above. However, rather than Berlin being vaguely the 'World Pro Championships' - it was universally and unambiguously regarded as such. Your above mentions maybe some promoter 'talking up' the event (though it was reasonable to call the Wembley event the World Pro indoor). In contrast universally Berlin in 1932/33 was called and regarded as the World Pro. It was a major at the time, regarded by all as such.