Hi - I just found the needles the shop in ME sold me for the Juki 2010: Schmetz special HaX1 SP. From looking online, they appear to be serger needles for stretch fabric and are definitely longer than the Organ. I suspect they'd be dangerous to use if they're longer. I don't own a serger.
I've been in the shop several times, and it always seems like they can't answer a question fast enough and then head back to whatever conversation or project they were into before. Without the expertise on this board, I'd have had no idea needles even came in different lengths.
hugs,
charlotte