Well, this is interesting. Some budding poet has written a few verses about Josef and his execution. While the poem is short, there is an interesting discussion in the comments from other readers. Most are quite taken with the line:
… but died he did, and the chair never healed.
Indeed, a moving line.
I would say that most of the commentators are not entirely knowledgeable about the Double-Cross system. The idea that Josef was betrayed by a Welsh Nationalist is a bit of a stretch. Agent SNOW was a double-cross agent… some would even say a triple or quadruple-cross agent. His loyalties have never been firmly established, except perhaps to say that he was loyal only to himself.
N.B. 2021 05 28 – I revisted the site and the poem is attributed to Ray Pool.