If you're going ask about mold to handle fit/interchangability then you need to specify if the mold is an old style small block single cavity. Or a double cavity. The old small block took one size handle and the double cavity another.
They are referred to as small or large handles. The THOMPSON CENTER mold handles will also fit the small block LYMAN/IDEAL molds.
Today LYMAN no longer makes small block molds or handles to fit them.
They now refer to the 2 sizes of handles they make as LARGE & FOUR CAVITY.
LYMAN switched names stamped on their molds from IDEAL to LYMAN in the early to mid 1950's.
LEE handles do not always fit every small block LYMAN mold.
I think LYMAN made small block&handles into the late 1970's or even later.