Yikes! With those compression numbers you're going to have hard starting. Typically once you drop below 200 PSI the engine will have difficulty even maintaining idle if you can get it started.

It's unlikely that a chunk of carbon fell into the cylinder, the injectors shoot into a prechamber, so there's no direct connection to the cylinder from the injector area. If the carbon chunk fell off, it fell in the prechamber and burned.

The injector tip you show is pretty knackered. If the rest are like that, I'm surprised the engine even ran! Surely it was nailing and smoking?

Might be looking for a healthier used engine if you intend to keep the car going.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]