You say Thomas was born 1855 but John was born 1852/53 so I can’t say they are one and the same nor can I be sure the 1851 entry is the right Robert.
I have known instances when a child has 2 christian names and is known by their middle rather than first one. I haven’t personally come across a complete change in name but I’m sure it must have happened at some time.
I believe I was basing the 1855 date off the later censuses where I can be 100% certain that my Thomas appears. In the record of his marriage from August 1885, he gives his age as 31, which would suggest a birth year of 1854 or 1853. So the birth year could potentially match up with "John", though that still doesn't explain the change in name.
It's all very weird but I doubt I'll ever know for sure what went down to make everything so muddled, but evidently something did! Thanks for all your help.
