Provided you havn't cleaned or polished the 2 halves you should be able to see where it was seated once you re fit the Bi-metal spring to the choke control lever.
A general rule of thumb is to re fit the spring onto the lever , then rotate the element body clockwise till the choke flap just starts to move from being in an upright position towards the closed position, we you are happy nip the screws up.
Regards
Fritz,,,,,,,,,,,,
One day you will find me,,
Driving in my Camper,
With a Surf and Paisley wrap on both sides....