Here is a must-buy for me! https://www.amazon.co.uk/Spanish-Piano-Trios-Trio-Arb%C2%A2s/dp/B07DTGPRDJ/ref=sr_1_4?s=music&ie=UTF8&qid=1533025885&sr=1-4&keywords=spanish+piano+trios (https://www.amazon.co.uk/Spanish-Piano-Trios-Trio-Arb%C2%A2s/dp/B07DTGPRDJ/ref=sr_1_4?s=music&ie=UTF8&qid=1533025885&sr=1-4&keywords=spanish+piano+trios)
Thanks, Martin. I think this is my kind of music, too. I am familiar with the Granados trio from a Beaux Arts Trio recording on Philips.
As to date besides, Malats died in 1912, Pedrell's nocturne-trio seems to have been composed in 1873 ("F. Delpler", a permutation of his name, on the manuscript - perhaps a little joke on Franz Doppler too or am I reading -way- too much into that?...), and his Elegia a Fortuny (http://mdc.csuc.cat/cdm/ref/collection/partiturBC/id/40176) (see link for digitization) dates from 1875. So probably within our rules, these works, too.