Glad Becky worked. Becky S. was the Girl of my Dreams in 1948.
Just to be my usual contrary P.I.T.A. metallurgist, I might say that through history most frizzens were of low carbon wrought iron, with a steel sole forge welded or brazed on. A few of mine are so done.
Brazed sole on frizzen of "rifle #3 Plates 93 & 94, st. John collection,
The Kentucky Rifle by Capt. John TG.W. Dillin.
These days an old hand saw or cheap circular saw blade would make a good sole. Hammer it to shape, use one or the other current versions of soft solder so as not to draw the temper.
I imagine there are a few hundred other thoughts on half-soling a frizzen.