Hi Jan, Jennifer & Dawn,
Thanks again for the input, but the answers seem to raise another set of questions. From your sources I think that there may be the possibility, however remote, that there are two separate lines of Parry's with similar sounding families, both by chance (or not by chance) living in West London. They may have been distant cousins, there seems to be quite a lot of Parry's living in and around Fulham, Hammersmith, Chelsea and Putney.
One Walter marrying a Caroline and the other a Catherine may not an enumerator's mistake, but two different families. One living in Fulham and the other in Lands End which is in Chelsea (I stumbled sometime ago to a reference to a branch of the family living in Lots Road, which is in this area).
Richard's age/date of birth seems to be out by 3 years. If the entry for the marriage in 1852 is correct and Richard and Elizabeth were each 21 that would mean that they were born around 1831, yet if you look at the census data for 1841 when Richard was 7 this would mean that he was born in 1834ish.
Any further backgound information would be extremely useful or if you would kindly point me in the direction of possible leads it would, as always, be very much appreciated.
Regards,
Alan