In Sentry Fallen Sun CLOC says that he is rebuilding Sentrys Watchtower and an undisclosed location while he waits for his masters return...Sentry
has been back since then hasn't he? Have we seen or heard from CLOC since then? Do we have a built and functional Sentry Watch Tower somewhere on earth we just don't know about?
The only time we've seen Sentry since his death was when he was resurrected with the Life and Death Seeds in Uncanny Avengers. At the end of this, he flew off into space.
No, we haven't seen CLOC since Fallen Sun. CLOC could be in space for all we know.
But frankly, I'm hoping we never see either of them again. Ever.