The fabric is a water resistant tactel from UK Fabrics Online. It doesn't feel like it will be waterproof, so I don't mind doing something with lots of seams.
So far, I've put two pieces together three times (sew, unpick, sew, unpick, sew, bugger it, that'll have to do!) that curved seam was an absolute pig for some reason, and it's still crinkly, although I haven't trimmed the seam allowance yet. I've now gone to add the third piece (a facing for the edge of the upper front) and it isn't long enough and I can't see why - so I've simply cut another one a bit bigger! Time for coffee and chocolate biscuits before I do any more.
Have you got a pic of yours Tamnymore? Would love to see it.