Of course, these oil changes & valve adjustments are relative to the life expectancy of the engine. I think (hope) Jims 600 hr est is conservative, my oil ch schedule exceeds OEM specs, I am ballparking the depreciation factor to 900 hrs @ 150 hrs per year = 6 years.
The 4th-century Tomb of the Lionesses consists of a small chamber with gabled roof. The painting depicts flying birds and dolphins and scenes from the life of the Etruscan aristocracy. The 6th-century Tomb of the Hunting Pavilion shows the view seen through the transparent fabric of the pavilion.
The Etruscan civilization flourished in central Italy between the 8th and 3rd century BCE. The culture was renowned in antiquity for its rich mineral resources and as a major Mediterranean trading power. Much of its culture and even history was either obliterated or assimilated into that of its conqueror, Rome.