Thanks Shera - those witness names don't mean anything at present, but I shall squirrel them away in my notes, and they may end up helping piece something together later on.
That was the only marriage in IGI that seemed to fit at the time, I was a bit dubious but luckily their last child was born after 1837 and the cert confirmed Sarah's maiden name as Luckcock, so fairly sure we're on the right track here. Thanks again.
Oops, sorry, baptism was at Harborne, my bad. And a quick look on IGI shows a sister Eliza! jolly good.