I realise your message was posted some time ago so you may have made progress since then! I think your John Bowker might be the brother of Thomas Bowker who is my ggg grandfather. He was also born in Kendal and on his marriage cert his father (also thomas) is a wheelwright of Kendal. I have a census for Damside in Lancaster from 1841 showing Jane Bowker 45, Mary b 1815, Thomas b. 1820, Jane b 1822, Rebecca b 1825, Edward b 1831. Jane Bowker was born in Manchester and I think her maiden name was Rishton. I have been to the record office at Kendal(not far from here)but didn't manage to find any birth records. There must be some as on the familysearch site there are records of some Bookers who would seem to fit, so I obviously need to dig deeper.