I ran my e300 almost in the red before and my engine has near factory compression numbers. You're probably fine. Your uncle owes you a motor for driving that thing overheating. That is stupidity.

__________________
Only diesels in this driveway.
2005 E320 CDI 243k Black/Black
2008 Chevy 3500HD Duramax 340k
2004 Chevy 2500HD Duramax 220k