Morwen, I suspect that you are going to have to discover your own idiom for singing Calypso, for yourself. Just take your time, listen to your sources a lot, and sing the songs that you love a lot.

As far as discovering or indeed cultivating your own voice is concerned, my personal feeling is that the key may lie in not attempting to consciously 'imitate' your sources, but to simply immerse yourself in them.

If I sing a song with a great deal of Scots dialect, I do not attempt a Scottish accent, but I will 'trim' the dialect to a degree so as to make it fit my diction without making the song sounding silly. I don't recommend that you do this necessarily, as I think you're going to have to learn your own way of navigating the meeting point between these songs (including how they are traditionally sung) and your own accent and singing voice.