'The First of May' was indeed written by Dave Webber, on the way back from Padstow Mayday one year - when he first got together with Anni. The true story of the above - and I was there at the time - was that on May eve at The Ring o' Bells in St. Issey, Dave was asked by a local musician who had been playing and singing it for some years, to sing it, as he had asked various other people to sing particular songs that evening. When Dave finished, he was walking past the bar when one of the local women said to him, 'If I was you, my dear, I'd leave Cornish songs to the Cornish.' It's rare to see Dave speechless, which he most certainly was, but also very chuffed that she should think that it was indeed Cornish! She was somewhat mortified to be told later that he had in fact written it!
I daresay it'll be sung a few times around Mayday this year as well.