There's a bloke on Youtube Mr Awesome who watches my videos and comments on them. He's got his own Youtube channel and tonight he directed me to one of his videos where he demonstrates one of his variations. Either on here somewhere or over at one of my other blogs I've discussed and explained how my Top-Spinner is very different to my normal deliveries. I bowl it with a far more fingery action - not sitting deep in the hand but away from the palm. Watching Mr Awesomes video (link below) I realised that his leg-break is bowled in a very similar way to my top-spinner, But, he then points out a very nice little detail that I'd never considered, which once it's pointed out seems really obvious. Using Mr Awesome method and my Top-Spinner method, more purchase can be had on the ball by arranging the seam so that your finger rests on it in the way that he describes.
I'm definitely re-visiting my Top-Spinner and I'll be turning that seam around in the way he suggests and giving it a go.