Memoir / artist's letters?

I ahve a friend, now a very elderly lady, who in the 1950's was lovers for five years with the surrealist/expressionist Cuban painter Wifredo Lam, in Paris & Cuba.
She tends not to be mentioned in biographical sketches of his very much; but still has 35 of his letters, which she now wants to publish, together with a 120 page memoir she has written, by way of introduction.
She can write,she worked as a journalist for several decades, but she's not had much luck getting this published in the Spanish-speaking world.

I have been wondering, as interest in Lam's work is probably strongest in the US, whether it might not be possible to get the letters published there; I dont know if, what with the strong Cuban exile presence in Florida, there might not actually be Spanish-language presses, for example. Or obviously getting the letters & memoir translated.

I have zilch knowledge of the US art book market, any suggestions at all would be very much appreciated.

Muchas gracias

Oooops... didnt know that. That would certainly complicate things US-wise.

Not sure whether it's something to do with Spanish-language publishers, certainly as far as I know it's not come up as a possible sticking point yet, more that there's a lack of interest, publishers saying it's an interesting MS but not in their line, or that other things are currently in demand.

Will have a look into the copyright situation.

Cheers.