This is very strange. The 5/20 sisma went famous by this photo of the broken clock in San Felice, SISMI was involved in the broken clock of Bologna. And even stranger, Propaganda Due, the pro-faschistic pseudo Freemasons, too. Now look at the symbol that the real Freemasons used during Faschism: [link] And now look what I used as a symbol for a sisma shirt before I knew about: [link] Sisma, scisma, Fascismo, everything sounds the same. Sam Browne could write a new cospiracy thriller about it, "The Clock Code".
That "strange connection" has a rather trivial cause. The "broken clock" motif is an archetype of photojournalism with damaged buildings, no matter if by bomb or earthquake, it's a symbol for time freezing to a moment. If you google photos of bombings or earthquakes, there's a good chance to find broken clocks.
I know it's as U wrote... but watching that clock I see those 2 missing numbers, just those ones... for me, it isn't so much interesting the broken instruments itself but how it's been broken, which parts of it are damaged.
Aaahhh, THAT effect, the brain reconstructs missing parts of objects we know. Like we can still read a line of text even we cover the under or upper half, the brain repairs the letters. That's interesting, LSD can upgrade this ability of visual data recovery, strong electromagnetic fields can switch it off. With a magnetic hat, you could not longer guess the missing numbers.