Iv got a carb in working order (il check if its the same as yours) if you cant get a choke plunger its here
All TTR250 carb's are interchangeable. You would be better off selling the carb complete as it would be worth more and be a lot more useful then a carb with bits missing.
Just food for thought.
Jarrah
__________________
2000 TT-R250M-
Spoiler
Ported & polished, 73mm bore, Wizeco piston, US header pipe, FMF Q4, #150 main jet, #52.5 pilot jet, throttle stop screw adjusted, larger snorkel, GYT-R air filter, NGK Iridium spark plug, 14/51 gearing, NOS +