I cannot find a birth or marriage for John but I did find the following information, which may be helpful?
According to the baptisms for Jane 1813 & Richard 1818 John the father was a Woollen Manufacturer.
Catherine was buried age 3 weeks in 1816 abode Prendergast Mills, as was the first Richard who died age 1 day in 1817.
Jane was buried age 8 abode Priory Mills, New Haverfordwest.
All above records noted as BURCH.
Colin.