Going by the parts list, the original setup used a screw-in metal needle seat.
If this has been superseded by a 'soft' seat, the original seat would need to be removed, before fitting the new one.
Pics of the bits should permit us to sort this out.
Cheers,
Gadge
"ODK Mods can explain it to you, but they can't understand it for you..."
"Crazy can be medicated, ignorance can be educated - but there is no cure for stupid..."
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