G'day Wayne,
Sorry for the slow response... didn't see the post. The breathers in the photo are the fuel bowl vents. They are needed to allow the fuel bowl to breathe properly. The carb will run without them, though from memory if they are pulled out then the vents are under the choke plate when the choke is shut... not the end of the world, but not great either.
The vents are a press-fit. One of the main causes of them coming out is when dodgy overhaul shops use acid baths to clean carbs (to get rid of dirt, ready for nice shiny replating), or when ultrasonic cleaning is used too heavily (local cavitation is caused at some parts of the carb, eroding it). Ash (from the FX/FJ forum) has recently had the same problem. Far better to clean with kero/thinners and put up with a bit of residual carbon smudging (IMHO) than the have sexy shiny carbs with loose fittings.
Did you get the carbs profesionally cleaned or overhauled? If so, would be interested in a PM of who did the work (to compare to Ash's horror story).
My main worry is that the other carb may also be loose - grab the vent and give it a bit of a pull with a pair of pliers. If it comes out on the road, it may well get sucked all the way into the cylinder
.
Not likely to find a replacement/spare part for the tube alone - you would need to replace the air horn. I may have a spare air horn at home - give me a PM if you are interested.
Cheers,
Harv (deputy apprentice Stromberg fiddler).