Newer washing machines have less concrete in them that before - My guess would be that in the past the water tank would have been to large to actually fit the m

Newer washing machines have less concrete in them that before - My guess would be that in the past the water tank would have been to large to actually fit the machine. I also wonder how the plastic will stand up to the vibrations. You might get leaks because the plastic will flex and eventually rupture from stress. The reason why newer machines have less counterweight is that the motors are electronically regulated these days. That means you can partly dampen vibrations with the motor instead of with weights.