I am descended from that Thomas Helsby, I think it's the same one. My cousin Jim Helsby, in York, has some more daguerrotypes. I understood there was a photographic studio in Valparaiso, which my grandfather, William George Helsby, sold in the 1920s. During the nineteenth century some of the Helsbys criss-crossed the Atlantic (one at least is described as being 'of Valparaiso and St.Asaph', St. Asaph being in North Wales). Thomas Helsby of Liverpool, 1773-1849, married three times and had an enormous family, more than twenty children. I am descended from Thomas and his second wife, Anne Smith. Good luck with your quest!