Thank you, lizdb, for the information you have posted. I am inclined to agree with you that Elizabeth brought the money to the marriage. Thomas left in the region of £25,000 when he died in 1902. I have a copy of his Will; it's very long and detailed, but mentions no relatives. John Dainty of Leicester (executor and beneficiary) is not acknowledged as a relative, and the Will throws no light on how they knew each other. John's Will is similarly unhelpful! Many years ago, I saw a newspaper report of Thomas's funeral - he was buried with what appeared to be Druid ceremonial.
I have traced John's immediate family - his mother came from Scottlethorpe in Lincolnshire, and he named one of the houses which Thomas bequeathed to him "Scottlethorpe". The book of poetry which John wrote contains his autobiography, but only refers to Thomas in the dedication, and at the very end, when he mentions being called to Gloucester because Thomas was seriously ill.
I have accounted for all the Maisemore family, and they all belong to Thomas. Jane (aged 5 months in 1841), was his niece, and disputed Thomas's Will, but lost the case.
I find it interesting that Elizabeth, Thomas's wife, was 46 in 1851, and 61 in 1861 (and 71 when she died in 1871). There are two very similar parishes in Herts where she might have been born - Codicote and Caldecote, which I must investigate.
Anyway, thank you again. As I said, I don't think I am related to him, but just find him fascinating and would really like to find the "missing link" to solve the mystery.