I just bought me a nice 1995 E330 Diesel sedan - with 155,000 miles. Getting ready to get it registered so I can pay pay tax on it

From previous MB I've had the power steering reservoir has always had a guide in the rez to show where the upper fill limit is at 20C. This one is full to the top all the time - i don't think this is right and before I start siphoning fluid out to check I thought I'd ask if it is probably overfilled and what's the danger?

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dtf
1994 E320 Wagon (Died @ 308,669 miles)
1995 E300 Diesel (228,000)
1999 E300 Turbodiesel ( died @ 255,000)
2006 Toyota Tundra SR5 AC 4X4 (115,000 miles) rusted frame - sold to chop shop
2011 Audi A4 Avant (165,000 miles) Seized engine - donated to Salvation Army
BMW 330 xi 6 speed manual (175,034 miles)
2014 E350 4Matic Wagon 128,000 miles
2018 Dodge Ram 21,000 miles