The other problem I have is that, although my great grandparents arrived in the UK in about 1890 I have been unable to find them on any census return. My grandfather first appears on the 1911 census, but his naturalisation papers show that he was brought here when he was 3 or 4 - as he was born (in Plock) in 1886 I would have expected to find them on the 1891 and the 1901 - but nothing. There is absolutely no trace of my great grandparents on any census return.
But then, equally, I can't find them in the JRI-Poland records because I have no idea what their real surname was. They arrived as Klein - the reason for the change to Klein (according to our family history) was that it was changed by the German authorities at their port of departure who could not pronounce their Russian/Polish name and so substituted Klein as they were not very tall, but no-one knows what it was originally.