Are all emission parts still available for my vehicle

Engine would go from idling fine to barely running. All causes were said to be either ( or both) my emission parts were bad or the carburetor is bad.(Still not sure if I am looking at a throttle body). I have achieved best result from simply disconnecting the reed valve box attached to the air filter case. It is 3 hoses connecting to a metal box attached to the air filter. We had found it ran great with the air filter off then it would nearly die or die with the air filter on. So I unplugged those 3 hoses in the hopes to allow air. This worked and led me to believe the emission system is bad. Upon any searches for items like the reed valves I only came across blogs and threads about my needed parts only being available in junk yards.