The Huish Clan, can anybody help me.

[gilmore]

That is a very common tale. ...
If you say great grandfather, I'm guessing the early part of the 20th century like the Scottish part of my family. They possibly came in through Ellis Island, upon leaving the gang way of the ship and signing in and the officer might have dropped the Mc/Mac right then and there.

...

That too is a commonly told though usually untrue tale. More often the immigrants changed their names themselves in hopes of better fitting in in their new country.