The one with the longer magnet may be an aftermarket unit. FWIW, on mine the transmission fill and rear end tend to pick up the most fuzz once everything was broken in.
past afflictions include TR motocars and bikes, R60/2 & a R65, MGs, and a Citroen.
Now a 2012 FF GU and an 87 K75s
dual K&N cones on PVC intake, 40/137.5
$29 VW Hydraulic steering dampener