If the flowers have been pollinated then yes - so I suggest you leave the dried off flowers alone. If you have C.puniceus it will set seed automatically, and you should have plenty of seed. If you have C. maximus seed set is more variable, as it is more dependent on pollination vectors such as birds. After flowering the green pods should start to emerge within a week or so. Leave them until they mature and split open, then harvest the seeds. Good luck. Its nice to know people still grow this species and evidently treasure it.