Gordon's email is gcusens@hotmail.com
/index.php?topic=166855.0]http://www.[blank]/index.php?topic=166855.0 if you go to this address you will see the tang safety you were talking about, and the gunsmith who made it. He can do the magazine as well.
Good luck, and I look forward to seeing your rifle. I too am in the process of building a Lee Speed copy in a larger calibre, 375x2 1/2 probably, to go with my original BSA.
LesLeeSpeed