Yes, I always use mine when using the factory jack. I cover the jack holes with the 201 jack holes. The W123 never came with them but use these same jack holes fine (the jacks are pretty much the same size).
For lifting the car using a floor jack, I use a large 2 x 4 block of wood between the jack cup and vehicle chassis, about the same location as the jack points. The differential itself or the frame behind the oil pan works too with the block of wood on a floor jack.
