Finally the decision has been made.

Looks right, but I still would not buy it or any old use damper...period. A damper works to damp out high frequency torsional vibrations in the crank, like up around 6000-8000 cycles per second. See here:
Crankshaft Torsional Absorbers, by EPI Inc.

The damper works by having a steel ring and thin rubber connecting ring that are 'tuned' to operate to absorb the vibration energy in the crank at a particular frequency range. That frequency range is where the crank would want to resonate and where the torsional vibrations could build to crank breaking level.

When the rubber gets old and hard, then the 'tuned frequency of the damper changes and it will move off of the crank's worst resonant frequency and not be as effective anymore. As the rubber gets harder and cracks, then the damper just can't damp anymore and it is useless.

So now you know what can happen if using an old damper. If it was 5 year-old damper, then OK, but any old damper might be OK or it might not (probably not). With a 'lo-po' engine, you can get away with it. But IMHO you are moving up to 'mid-po' and at least ought to get a new basic damper like a basic Pioneer model. Maybe someone has one that is a few years old that you can get on the used parts forum. Yeah, I know...it's always sumpthin'....

BTW, any imbalance in the damper to provide external balance to the crank is a separate function of the damper.