The Trabant Engine is dead

My '83 Trabant drove wonderful the past 7000km since I bought the car in March 2007 as a present for my wife. The previous owner did not know the exact mileage. It already had a replacement engine. Well, now I know the base part of the engine is not from '83, it is from Oct. 1971. Almost my age.
The cylinders have a stamp from 1989. So it was probably assembled in the later 90's, more likely early 90s.
I was driving home in the evening last week on the 5th of March (bought it March 6th 2007). I was happy, that it happened right before the next Highway exit. Because about 1km after the exit there is no emergency lane. That is not a good feeling there I guess.
Since the engine made a loud noise and then the car slowed down immediately I knew, it must have been a stuck cylinder. I pushed the clutch and rolled out into the exit.
I put on my vest and secured the location. Called the ADAC (German car club, like AAA) and he picked me up. Hey, I just installed a brand new Battery and the tank was full :-(
Back home I removed the engine, gearbox etc. and now know, that engine is dead. Need a reworked engine now. The rest of the car is still in a good conditon. That is also what theCar Inspector told me last year.
Look at the pictures: