Kind've hard to tell, but it looks like there's a mark around the seal like a deformation where the sleeve bush could be interferring--, ie; not going inside the seal.
if you have all the right bits (bits that will ultimately work right whatever their origin
), you should be able to just put the bush on and screw the nut on/off until it binds or not.
The fact you are using a bush from the early model is exactly what I suggested earlier.....it's too big
This clutch was removed from an A7 long stroke motor
I'll assume you might've meant to write 'bush' instead of 'clutch'.
you could find a proper one, or have that ground down to suit (dunno if the longstroke crew would give their eye teeth for one ?)