My wagons sways much more than I'd like when cornering.

I had my suspension rebuilt eight months ago and put in Bilstien HD shocks in the front, but this didn't make a very noticeable difference.

My accumulators crapped out a couple months ago, which seems to have improved things on the swaying front, but obviously I can't let that be; I've already bought new accumulators and will install them ASAP because driving my wagon now feels much like riding a horse.

As far as I know my springs have never been replaced, making them 23 years old with 305k miles on them. Might they have weakened? I know from my searches here that leathermang will recommend I replace them... what does everyone else think? I don't want to sacrifice ride quality any more than necessary and I don't want to lower my car. If I do replace them, should I replace them with stiffer ones, or will new standard ones be enough of an improvement? Where do I get them?

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'81 300TD Wagon 355k (Miss Diesel)
'83 300SD 180k
'84 500SEL 190k (Parting it out)