Bev Potter had a good idea, as below.
Many thanks to Celia Male, Michael Hoffman, David and Mrs. Rubin- I love it,
she doesn't have a first name- and all the others who have offered their
ideas. I hope that I have answered everyone privately, as well as here.
I still haven't solved the mystery of Mysl. On the UK Passenger Lists, he
is shown as "Uryph" and on the Canadian Lists as "Mysl".
Thank you again to all who have helped.
"Bev Potter" <basha@...>
But I tend to wonder this:
When your father approach the counter and the clerk asked
'NAME?' - Perhaps your father (or his mother or father) said
"mmm, yussel" and the clerk wrote MYSL.