My concern with the lead screws on the outside is that it makes working the spring in and out of place that much more difficult. When fitting new springs, you'll have to clock the compressor correctly so the coil ends align with the perches. Nothing insurmountable.

Looks like it wouldn't be a lot of work to make a similar set-up with a single lead screw through the center but the factor of safety goes down.

Sixto
87 300D