I'm a bit confused about the Danish connection. Mohamddin/John seems already to have had a Danish surname (Peterson) before he married Margaret. I wonder whether:
1. Mohamddin had been married before to a Danish Miss Peterson (whose name he took), or
2. the generations have been mixed up, and Mohamddin was in fact (though born in India) half-Danish - his father having married a Dane and taken her name?
"
It is also said that although my partner's grandmother's father was Danish, there was some Scottish ancestry too, which would tie in with the McLachlan surname. There were several Peterson children born in Liverpool between 1923 and 1932 with McLachlan as the mother, including my partner's father."
Are you saying here that Margaret also had some Danish blood, or was she straightforwardly Scottish?
I also wonder whether Mohamddin's heroics were not in the 1920s after all, but were connected with the 1940 shipwreck? (After which he was taken to New York).
Anna
