Indeed. The panel has nothing to do with the clock, rather whether the clock itself was installed is the question.
That's quite an interesting point you made. Rather than the clock being a clock, it was rather controlled by the master clock, or Magneta clock, as with all of the clocks onboard.
If the frieze panel, Honour and Glory, was installed though, what would passengers have saw? The panel with simply a hole in the centre from where the clock should have been installed?
Or of course, the entire thing could have been complete in the first place. We will never really know for sure, unless of course some photographs surface which is quite unlikely.