Mikesamwild passed on the suggestion culled from Jon Boden's Folksong A Day site that the origin of the song Yellow Roses was in a competition winning poem published prior to the Spanish Civil War.I contacted the person who suggested this and she said she got this idea from a book in the Glasgow reference library which refered to a poem called Yellow Roses by J. Hooker Hamersley which had won a competition although no words to the poem were given. I tried to contact Glasgow reference library unsuccesfully but in the process was referred to the Ask a Librarian Service.

The ASK A LIBRARIAN web service found me the following link to the volume of poems called Seven Voices by J. Hooker Hamersley, published in 1898 and published now on the web by Google Books. On page 3 is a poem called Yellow Roses but its words bear no relationship to the lyrics of the song we are discussing in either of its two recorded versions. If you want to see for yourself click the link and then click the PRINT option on the left side of the page and then the pdf download option which appears.
HAMERSLEY'S Yellow Roses

The same informant gave me the link to Trevor Peacock's agent and I am still awaiting a response to my enquiry in that direction.