Hi Paul,
thanks so much for confirming whose duty it was to report Births from 1837 until 1874, and that it wasn't the parent's responsibilty. To have a Registrar roaming around does seem a rather random way of doing things, no doubt he visited the churches too for Baptism records but even so plenty of room for error I guess, which rather matches my own thoughts and findings on the subject.
Thanks again, J.