I have only one reference to John Allcock that I think is probably relevant to your line of inquiry. In the 1841 Census a John Allcock was recorded as living at Headless Cross with my ancestor Edward Allcock. Both were recorded as aged 15 and gave their occupations as needlemakers. Edward was also born in 1824 so the census age should not be taken too literally. I wonder if this is the same John Allcock? Unfortunately I have no further information about him but I think that it is fairly likely that they were related. The Census reference is HO 107/1197 Parish of Feckenham page 21. I was able to view it at the Public Records Office in Chancery Lane but that was about 30 years ago! I have not attempted to access this census over the internet but that may well be possible now.