I'd really like to know more about the cylinder itself - I think it might have as much of a tale to tell as the body, and it's a shame there aren't better photographs.
Is there any non-vague explanation as to what it might have been, and why it would have been in that location?
Maps of the area at the time of T C Williams' disappearance suggest that the area consisted of dense terraced housing, rather than industrial units (see the link in Souleater's post #43). But the 1851 map (below) shows a less densely developed area which might be more likely to contain industrial works (the sand pit might also suggest some sort of industrial use in the locality). There is also what appears to undeveloped space around where the Methodist Chapel would later stand, and immediately north of it - the area where the cylinder is said to have been found. I wonder if there's maybe a chance that the tube could have been an artifact of this earlier time, surrounded or obscured by later development.
View attachment 33807
Also, there seems to be an assumption that because the cylinder was discovered horizontal, it must also have been that way inclined for its intended use . Could it originally have been vertical? If so, this would add another form of misadventure to the list of potential reasons for a body being inside - people fall inside things and seriously injure themselves all the time.
I suspect the crumpled end is a product of later development related disruption, or the bombing and it's aftermath - and that the body was drying away in there long before it's means of escape was sealed.