Rough engine vibrations issue resolved by 75%.
Solution: ChrisFix video "how to test plug wires".
Distributor looked perfect, but was arching very badly when i "sprayed" some water on it in complete dark. Removed the rotor and cap and then inspected closely to find cracked (not broken) rotor and cracked distributor cap.
Rest, one plug wires was arching, but resistance and visual inspection actually passed it.
Re-soldered the ignitor wire which broke during work and then car would not start.
all faulty items replaced. issue almost resolved.
remaining issue is due to hard engine mounts.
Acceleration, idling and efficiency further improved after replacing wires, cap and rotor etc.