Timing Chain takes out another 420SEL

Last week the Timing Chain on my 1986 420SEL with 212K miles skipped when my wife tried to start the car. She did not notice any loud or unusual sounds while trying to start our 420 just that it would not start. When I arrived home from work I tried to start our 420 but it would not start and would just turn over as if there where no spark.

I had the 420 towed to the MB dealer. After inspecting the timing chain, pulling the left valve cover, and a compression test they reported that the timing chain skipped and that there is evidence that some of the vales bent on the left side. (The result of the compression test (cyl:psi): 5:0, 6:0, 7:0, 8:0, 1:75, 2:125, 3:100, 4:125.) They stated they could rebuild the top end but that could cause problems with the bottom end.

The 420 was my father’s car and I would really like to keep the car but I’m not sure about the condition of the bottom end. Additionally before the timing chain problem the car was leaking oil and the AC had gone out. If I have the top end rebuilt I still have the additional costs to take care of the oil leak and AC.

Questions:
1. Does the result of the compression test give any indication of the condition of the bottom end?
2. Does the leaking oil give any indication of the condition of the bottom end? The oil leak appears to be coming from the main seal but the leaking could be from other places as well.
3. What should the psi rating be for an engine in good condition?
4. Any general advice?

Thanks for your help,

Robert