I've been trying to search online where I can find the FE1-specific replacement suspension parts that maintain that soft ride my dad's 06 (supposedly) came with from the factory.

He had rear suspension replaced at the beginning of this year but it never improved the ride and is also very loud/squeaky oftentimes, like some joints in serious need of glucosamine supplements. I can't seem to find suspension parts anywhere that specify they are the soft ride type versus FE3/sport or whatever the other option was that was available (FE2 I believe?)