Here's an interesting tidbit from the USA/NA MB EPC:

The Sportline Wagon's front springs (124.321.29.04) was also used on the 124.020/300E; 124.051/300CE; and 124.052/E320.

The Sportline Wagon with self-levelling and the low-point rear spring (124.324.23.04) was used on the Sportline 124.030/300E and 124.032/E320 with NO self-levelling.

The Sportline Wagon with self-levelling and the high-point rear springs (124.321.28.04) was used on the Sportline 124.051/300CE with no self-levelling.

The Sportline 300CE with self-levelling used a 124.324.27.04 (low point) or a 201.324.36.04 (high point) rear spring (are these springs stiffer and/taller than the Sportline Wagon's rear ?).

So, it seems like there are various springs to use in a SportLine setup of the wagon, depending on the points.

:-) neil