Further Improvements
The photo shows the modifications I applied but this would not normally be done as a standard repair.
It was purely an experiment applying first principles to improve system stability and reduce EMI.
The modifications include the removal on unnecessary capacitors, the addition of links, PCB breaks and localised Coulomb bucket capacitors.
Here is the final result.
As you can see the noise has gone and the picture is stable as a mountain.
Conclusion:
Polymer capacitors are suitable for vintage designs but are best used as a direct replacement for old components that have lost their original properties or to replace components that pose a fire hazard.
Slight improvements can be achieved from the superior ESR and ESL properties.
The available values are generally too large for effective high speed noise reduction but this is no problem for newer designs that incorporate suitably designed power planes and controlled impedances.