Yeah the only real fix is a trans rebuild. If it bothers you that much have them yank the trans and rebuild it. 20 year old trans have 20 year old seals and will leak a bit. Or just live with it, old cars just do that and trans fluid is cheap.

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2006 CL500
2009 C300 4matic
1969 280SE
2023 Ram 1500
2007 Tiara 3200