From the movie Infinity War, this shot clearly shows two moulds being filled during the casting of Stormbreaker:

After Eitri thumps the mould three times, both halves are seen amid the pieces of one mould:

Do we have any indication from movie cannon, comic, or press statements as to what might have been in the second mould? (Eg. Love and Thunder spoilers?)

^{Both pictures taken as screenshots copyright Marvel studio's Avengers: Infinity War 2018, fair usage.}