Check ebay frequently. There's always people selling parts from older/rusted/damaged tools.
Don't just rely on what parts are listed, but what parts are listed for that Brand of press.
Somebody may have listed a different part for that press, but not that part.
Sometimes they may not list it, believing it's not a 'demand' item.
Contact them and see.
Also check sold/completed listings for that type press & inquire.