Hi Lawrence,
It won't help your enquiry but I'm a relation of yours on the same quest. I'm descended from Henry's son William who married Sarah Laws (as indeed you may know). I have rummaged SMO registers at the Forum and frankly can find no reference earlier than Henry Nichols Reynolds baptised 16.12.1799 Pockthorpe St James out of wedlock, the marriage being SMO 09.11.1800. I wonder if earlier data may be in the St Pauls registers or transcripts as this is where Henry Nichols Reynolds was baptised. Of course there is a problem of water damage in the blitz in the case of St Pauls and some records are irretrievably lost. You can check on-line what is available. I know there is a printed transcription of the surviving water damaged registers. Meanwhile I would be fascinated to share data with you. If you give me your e address I can send you what I've got.
David.culley@dsl.pipex.com