I didn't get seed on mine last year Paul and this year doesn't look better so I can't send more at present. It's odd - and annoying - that some of the prettiest vulgaris forms don't want to set seed and have to be encouraged. Louise Salmond's comment yesterday was that the old 'Pink Denim' strain (which comes pretty much true) needs hand pollinating and also lots of water at this time. Worth thinking about. She also had a brilliant red with almost black/red inner but lighter, bright red at the petal tips.
I have a seedling which appeared like Topsy, and it is pale blue, a really good blue with very compact foliage. It just about looks like a hybrid between PP. vulgaris and vernalis. Needless to say, it too is not setting seed.