Video by Vespa Motorsport via YouTube
Source
6009605 For 2005-2014 GTS and 2018 to current fork
https://www.scooterwest.com/steering-column-assy-gts-6484155-1c0004295-6009605.html
1C0006215 2015-2017 GTS Only
https://www.scooterwest.com/steering-column-fork-assy-gts-2015-2017-abs.html
006422 C-clip
https://www.scooterwest.com/cir-clip-front-wheel-axle-for-20mm-fork-006422.html
012789-B Cotter Pin
https://www.scooterwest.com/cotter-pin-for-hub-nut-on-most-all-modern-vespas-1.html
285536 O-ring
https://www.scooterwest.com/oring-for-oil-drain-nut-285536.html
019264 Dust Shield
https://www.scooterwest.com/dust-cover-or-grease-cup-for-lower-steering-bearings-019264.html
152023-SET Complete Bearing Kit
https://www.scooterwest.com/vespa-steering-fork-bearing-set-upper-and-lower-152023-set.html
GREASE
https://www.scooterwest.com/maxima-waterproof-grease-16oz-tub-grease.html