The previous comment is not right, actually. Apart from a foreword by Herbert Read and an Introduction by the translator which both appear in the original 1956 edition, the actual text of the 2005 and 1956 editions is the same, minus some minor changes such as splitting a paragraph into two and the like. They are just typeset differently: the 1956 edition is an old-fashioned, hardback print with a large font, whereas the 2005 edition by AK Press has been reset to a more modern standard and contains fewer pages (it is also a paperback). But the material itself is in fact the same translation of the original text by the same translator, I can assure because I have contrasted both editions (and I should state that both editions explicitly state that the text is an abridgement of Rocker’s overall memoirs, published in Yiddish in 1952, though this is by the by, as the 2005 edition is simply reporting information from the 1956 edition; the 2005 edition even reproduces the drawing of Rocker’s from the 1956 edition).
As for the claim that Rocker was displeased with the translator, I am sceptical. The translator was a family friend and in the Introduction to the 1956 edition he reports that the Rockers were in fact quite pleased with the end product. Plus, it’s not at all obvious how he is being made more moderate or less radical at all – he sounds pretty much as in many of the other biographical writings of his I have read.