How to kill Mockingbird(560sel)

Some of you might know that my 560 sel died suddenly few week ago. Now I know what happened. I will come to this latter but at this time I will try to describe the chain of events that happened.

I am auto mechanic by hobby as part time. Although I enjoy full time job in Health care industry. One day I was working on gas tank of 1968 Mustang. I siphoned all the old gas from the from the tank in a plastic gasoline container almost 10 gallons. Because of my Greed and ignorance I poured that gasoline in 560 sel gas tank. Owner of Mustang did tell me that gasoline in his Mustang is more than 10 years old. I drove 560 sel though out the day without any problem. Next day in the morning engine died. Lot of rattling noise, most of the valves stuck, most of the piston got stuck. Engine locked up. There were no damage to the upper chain guides and no timing chain stretch. How do I know this? I used same gasoline in my Goped and same thing happened to goped engine. So Bad gasoline means lot of gunk, lot of varnish and very very foul odor gas. Due to my greed for few dollars, I kill my 560 sel. Now I can not recover this car because I ruined piston, valve and jumped timing chain without breaking upper timing chain guide or timing chain stretch. May be it also gummed up the fuel filter and fuel pump God knows what not.

I learn this very, very, very----- hard way.

Lesson to learn from my mistake rather blunder.

NEVER EVER USE OLD GASOLINE ON ANY CAR. I can not forgive myself for this mistake. The bad part is this, I can not tell this to my wife and daughters. What a stupid I am?