A23 Petcock

A23. 12x1 female side mount Ciao

A23 12×1 side mount 5320   $18 
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Italy-made by Franconi

A23b 12×1 side mt. 
01Z2141023A  $18   
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 Italy-made by OMG

Links to photos of examples:

1974 Vespa Ciao frame

This valve fits a Vespa (Piaggio) Ciao. It can also fit a Puch Maxi type frame, but the upper filter hits the inside upper wall of the Puch gas tank. The reserve tube, which is a light press fit, can simply be rotated so it is not aimed straight up, to allow a Ciao valve to fit a Puch.