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.
Admittedly, some of these languages have tiny populations, but they are living monuments to the past. Just like you may see an Etruscan tomb from the second century BC, 2200 years ago, or a Roman temple from 1900 years ago, in Italy today you can find, people who speak a language that hearkens back to ancient times.