A19. 12x1 female spigot back short extended knob
A19 12×1 spigot back with short shaft
Left is original, right is replacement
It is a A15 with a longer handle shaft $27
←reserve on↓ off→ OMG made in Italy
Links to photos of examples:
1985 Garelli Rally SL original
1985 Garelli Rally SL original
Garelli 1980-86: This valve is made for the 1980-86 Garelli Sport, Rally Sport, Rally SL step-thru models with side panels that cover everything up to the bottom of the gas tank. The valve handle shaft passes through a hole in the panel.
The replacement sticks out a few mm farther than the original. Not bad.