Tomb it may concern (was: The eyes of a clone)
Apologies for the change of thread, but I wanted to distance this from any discussion of clones.
It's Severian's tomb. At the end of Citadel, talking about the 'other Severian', he says that he "became himself a walker of the corridors [of time]. I know now the identity of the man called the Head of Day.... I know too in whose mausoleum I tarried as a child, that little building of stone with its rose, its fountain and its flying ship all graven. I have disturbed my own tomb, and now I go to lie in it." Citadel XXXVIII
That last sentence pretty much says it all.
After Severian brings the new sun he has both the ability to travel in time and the ability to resurrect, so there's no reason why he couldn't leave tombs all over history. And as someone who has already brought the new sun, there's no reason why he shouldn't include a white fountain in his coat of arms when he does so. (It would be a bizarre thing for Ymar to do, on the other hand.)
To answer your point, Roy, about Severian in Apu-Punchau's chamber looking so much like the figure on the funeral bronze... I think that's just to underline the fact that Severian has now reached the age when he's about to start his time-wanderings.