oil level & noises

Help!
I have a 69 911t with a 2.0 liter. I know 2 cylinders on the same side have low compression numbers. I plan on replacing the engine in the near future. The problem right now is that after having driven this car for the last 3 or 4 months is that suddenly the oil level gauge has shot up into the red, indicating to much oil in the system, and a mess in the engine compartment. It has never done this before, the oil level was always showing a correct level.At the same time it started to make the dreaded chain rattleing noise from the rear end. Could one of the chain ramps have broken and become lodged in the oiling system? I plan on removing the covers and inspecting this weekend, any other ideas of what to check would be greatly appreciated.
Thanks

------------------
69 911t
86 951