And, no, I wouldn't expect "and more" to be an exact age. I'd expect something like 24 years on such and such a day last ... to be exact. The more I think about it, I think the only resolution is to turn Thomas into Nicholas, the brother and executor of John, but whose somehow not the heir with that exact relationship stated in IPMs, and then detach the current Nicholas as parentage unknown. No verifiable Magna Carta line.