I pull the motor out of the 86 300SDL deer slaying parts car. (603.961)

The compression:
1 - 110
2 - 410
3 - 380
4 - 380
5 - 380
6 - 350

A wet compression test brought #1 up to 220. So, I suspected the rings are impacted.

I pulled the motor and have the #1 piston out. I am happy to report that it is the rings.

Here is what I found when I pull the the head:
Each piston has a "10" stamped on it.
There is an "X" stamped on the block above each cylinder.

I assume this means that each cylinder was bored out and that they were bored out 10 thousands over.

If I am correct, then I will need to order a ring set that is 10 thousands over.

So, can anyone out there confirm that I need a ring set for 10 thousands over pistons?

Where best to get the rings?

Thanks,
Greg

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Greg
2012 S350 BlueTEC 4Matic
2007 ML 320 CDI
2007 Leisure Travel Serenity
2006 Sprinter 432k
2005 E320 CDI
1998 SLK230 (teal)
1998 SLK230 (silver)
1996 E300D 99k, 30k on WVO
Previous:
1983 240D, on WVO
1982 300D, on WVO
1983 300CD, on WVO
1986 300SDL 237k, 25k on WVO (Deerslayer)
1991 350SDL 249k, 56k on WVO - Retired to a car spa in Phoenix
1983 380 SEC w/603 diesel, 8k on WVO
1996 E300D 351k, 177k on WVO

Just a SWAG, but I think Mercedes parts are all metric, so my best guess is that "10" indicates 1.0 mm overbore.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.