G'day CM,
Yup, the deco valve is missing, and it's the NLA new 'long' type.
Easily picked up on FleaBay, and rebuild kits are available too; here's a 'how to' I wrote up on the rebuild:
https://www.outdoorking-forum.com.au/forum/u...ssor-valve-rebuild-how-to.html#Post85918Carby exploded diagram is here;
https://www.outdoorking-forum.com.au/forum/ubbthreads.php?ubb=showflat&Number=11468Shop manual excerpts are here;
https://www.outdoorking-forum.com.au/forum/ubbthreads.php/topics/54967/victa-engine-parts-list-and-manuals.html#Post54967
The contacts are the 2 brass parts in the connector. There is a plastic spring you can't see when it's assembled, that normally holds them out of contact. 'Earthing' connection is via the throttle cable inner, to outer, to cable clamp on the carby body.