Thanks Elwyn, Thanks Andy,
Apparently, the earlier Jewish immigrants found it hard to get work in the UK, USA & SA, so they Anglicised their names & Jews from anywhere in Europe 'said' they were from Germany, because German Jews were better cultured, educated & so, got a better job etc... but, as things turned sour with Germany, they quickly changed their place of origin to Russian/Polish etc... But, once identity cards & the alien registration began in 1916, as you say, it would have been difficult for Jews to lie about where they came from. His alien registration information from the Dublin police book, gives his identity number & his place of origin as Russia, not Germany. So, maybe he 'said' he was from Germany to be better thought of, as he was always self-employed & he worked hard & prospered. Or, as has been said, perhaps his homeland changed hands after he left.
I have a friend who works at the NA & she has searched for Naturalisation records, but found none. So, I don't think the Louis Freedman from London would be him Andy, it is a very common Jewish name. He moved to Liverpool from Leeds in 1893 & apart from this appearance in Dublin, he remained in Liverpool until he died in 1949.
HR2