Tow truck just delivered the SL. Wouldn't start while wife was running errands. Looking under the hood I find the left cam cover cracked over the chain. Pulling the cover, I find the a piece of the upper guide stuck between the chain and the cam gear. A few more pieces visible in the chain run. I will get into the Maint CD this weekend. Looking for the best course of action. Hoping I can confirm the timing marks are still aligned. If yes then I am assuming I don't have valve/piston interference and can just repair the chain/guides. Correct? Or do I need to do a compression check before I get it all apart?

Assuming I will have to pull all the front covers to collect all the broken bits. Yes/no?

When I bought the car the PO gave me a receipt showing the chain/guides were replaced about 80K ago. From what I can see, the guides are dark brown and look pretty brittle. Think the PO got ripped off. Was hoping to get several more years before I worried about the timing chain at around the 100K mark.

Any tricks I need to know that aren't in the Maint CD?