New 20 ounce tumblers available now! Forum donation credit with purchase. https://www.wildguzzi.com/Products/products.htm#Tumbler
Pretty sure you need the key to depress that spring loaded pin. Here's some information that might help (or not).https://www.thisoldtractor.com/moto_guzzi_tonti_v7_sport_ignition_switch_replacement.html