Very much tighter than mine, without the marker variables. Nice. I think the only feature of mine not reproduced is that I put the conjunction into the second half, i.e. you get

a more convincing image of the truth of the ancient state than
any they have left by the Tiber.
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in yours but

a more convincing image of the truth of the ancient state 
than any they have left by the Tiber.
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in mine. Plus I'm wary of the \W in your "break on punctuation" picking up unwanted things. But thanks!