Here is the scenario:

1. Unaware of oil leak...but oil was slowly leaking causing engine knock

2. Started engine on a cold day (50 degrees) and the engine sounded like a lawn mower (sound of low or no oil)

3. Shut engine off...filled with oil

4. Tried to re-start....no luck

5. Shop told me "Timing chain broke, compression lost" but that was it on the diagnosis and told me to get a new engine or new car.

Should I .....replace the timing chain in hopes of revival or replace the engine?

If the timing chain broke, the engine would just spin really fast, does it do that?? If so timing chain broke, and more then likely hit the valves and such. IF thats the case either way it goes, it will cost. But not too much, and also depends on the engine of your car. You can find both engines (LN2 and LD9) at junkyards for very cheap. I would just buy the new engine, throw it in there and call it a day. But I would do simple maintence to the new motor before you drop it in. Do the timing chain, do the water pump, oil pan gasket, and all similar gaskets and stuff, so the engine is as fresh as you can get it without rebuilding it and such. Goodluck!