I noticed some points in the compiled news articles (linked above) that don't exactly match the exposition cited by the OP.
RE: T. C. Williams' Son
According to the
Evening Express of 31 August, 1945:
The Coroner said Inspector MORRIS had been in formed that Mr T. C. Williams had a son born in 1859
Dr FIRTH said it was the body of a man between the ages of 30 and 50 and it was not reasonably possible to believe that it was the son of T. C. WILLIAMS.
(Dr. Firth was not the coroner. He was Director of the Home Office Laboratory, Preston, and presumably involved as a forensic consultant.)
According to the
Evening Express of 19 July, 1945:
Dr Charles Victor HARRISON, senior lecturer in pathology at Liverpool University, said the cranium was broken in the region of the left middle ear, but there was no reason to think it had been caused by violence.
He thought the body was that of an adult man, about 6ft in height, and more than 25 years of age but not more than middle aged, and that it had been lying there for a long time.
This would seem to rule out - or at least increase doubt about - my suggestion that the corpse may have been Williams' son.
RE: The Railway 'Ticket'
The alleged 'ticket' from a railway has been taken as a possible clue, because folks can't imagine why (e.g.) a getaway ticket might have been left planted on a substitute corpse.
As it turns out, there was a document from a railway, but it wasn't a ticket. The sole reference to any rail-related item found on the body is as follows:
There was also a London North Western railway advice note dated June 27th 1885, and what appeared to be an undated bill head of T. C. WILLIAMS and Co, Leeds St, Liverpool.
(Emphasis Added)
An advice note is a notice sent from a supplier or vendor to a customer, typically used to advise the customer an order has been fulfilled and / or shipped. I can't locate anything indicating such 'advice notes' were issued in relation to personal ticketing for rail passage.
It would appear the claim the corpse had a ticket for rail passage is erroneous.
RE: The Cylinder Itself
As I understand the newspaper articles, the cylinder itself was never clearly identified. It seems multiple people suggested it might have been a former ventilation shaft, but its original purpose and provenance were never established.