If it was something Steve Ditko was entitled to he would have reclaimed it years ago. This is a cynical move for a pay off made by Steve’s brother who never created shit himself anyway.
Steve Ditko was an Objectivist and believed in payment and trade for work done. If he believed he was being stolen from he would have done something about it while both he and Stan Lee were alive.
Personally I have noticed that after Steve Ditko quit Marvel he never did anything with mass appeal or indeed any proper comicbook ever again. It seems strange to me. Either Steve was creatively dry or he was burned by how Marvel and Stan treated him. He refused all interviews and became a near recluse.
Patrick Ditko just wants cash for doing nothing and is entitled to nothing. After all it can’t be a coincidence he has pulled this when a Spidey and Doctor Strange starring movie is no coincidence. They sat there at home and said, ‘Hey my brother was involved in creating that! Maybe I can cash in!’