Hi everybody ,
Sorry for the late answer. In one illustration the artist gave the Brodie helmet to a British Bataillon member. Did he bring it from home or was it given in Spain, who knows? The artist doesn't give any photographic support to his interpretation. (see attachment)
During the 1927 Shanghai Events, the Spanish sailors detached to the legations security wore Brodie helmet and 1914 British canvas pouches, AFAIK these gear was given by the British. I saw a drawing many many years ago in the Madrid Navy Museum and cool pictures in a Spanish forum.( Sadly the pictures were removed)..
Maybe a few Brodie helmets landed in Spain during the civil war but it seems not in any significant number. The loads of pictures show the aforementioned Spanish, Italian, Czech, Adrian helmets.
Cheers