Peter.
I kept the question short because the long winded version might be deemed to boring to trawl through. The key here is that he started in Connolly's Column but there is no record of him joining up, nor is his name listed amongst Irishmen who joined the cause. There is a photo of him availble in the book 'The XV International Brigade.' However, he stated when alive that he also served under Tito (then Josep Broz). I know of others that served in the Brigades that are not listed in official records as those that served. Would some have changed their names before travelling to Spain? Or were records not assiduously kept?
My information was that he was demoted for striking a senior officer, possibly whilst with the Connoly Column, which would explain why he might then have joined the Eastern Europeans.