Lambretta round nylon/plastic washer - set of 8 - sits under seat hinge and catch
Made from natural nylon. Top quality part, from Scootopia. Sold as a pack of 8, usually requires 4 under the seat hinge and 4 under the bracket.
See here for singular washers: http://www.lambrettaupgrades.co.uk/apps/ webstore/products/show/4285519
Price includes VAT @ 20%