Just looked through my stash of random parts and couldn't locate the stock carb bits. I must have tossed them out during the move.
It is a pretty simple system on those and honestly I'd be suprised if it's broken. You can pull the three retaining screws off that choke cap and inspect the spring if that's intact, hooked around the pin, has a decent seal (it pulls some vacuum from the carb) it should work when given 12v.
Have that black cap centered on its adjustment points (half way between the + and - marks) and tune it in from there. Too much to the + it'll be hard to kick off the choke, too much to the - it'll kick off too soon.