With NO dispute as to your (absolutely-correct) FACTS, many salvage yards will NOT sell used emission-system components. Depends on the particular state, respective to their particular legislation/regulation, in force.
With my residing in the South, we have far LESS regulation here, in general, respective to vehicle inspection. My sister, she lived in Florida, for awhile. Once upon a time, the state of Florida had vehicle inspections. Problem that state officials subsequently learned was that, so many of their "compliance inspectors" were corrupt. Accepting bribes from ticketed vehicle owners, they could be "bought off." So, the Florida Legislature "ditched" said vehicle inspection program. (Florida residents: Please correct me if they have since reinstituted vehicle inspection laws!)
Where I reside (in Alabama), we have a LOT of vehicle legislation in force. Examples given: Minimum tire-tread depth requirements, underage child seating requirements, and mandatory seat belt use (for ALL occupants). But Thank God we DON'T have the legal NONSENSE which fosters outright CORRUPTION...and is essentially non-enforceable, in the first place!
(I rightfully suspect I should be keeping my big mouth shut! Our illustrious Governor (Mr. Bob Riley) may be reading this post! And I certainly don't wanna give him any ideas!
On my trusty '86 (now some 23 years old), the catalytic converter is ORIGINAL. Yeah, I've got a brand-new replacement unit, in storage. But I won't be replacing it, except at Federal "gunpoint." I should add that (since its engine rebuild), my NOx and unburned HC measurements (at the tailpipe) are running about plus or minus two (2) percent, with a 95-percent confidence interval, using a Standard Deviation of One. This, you understand, is per 49-state exhaust emission specifications, for model-year 1986.
Bruce Hawkins: I don't know where you reside, and (personally) don't care, either. But if you'd like me to attempt to locate you a used "Cat," on the cheap, I shall be happy to accomodate you, Sir.
If a tree falls in the forest, and there is no one there to see/hear the event, then NOTHING happened. Catch my "drift?"
Being an "Inga-Neer," I can...and will...FIND a way to solve most any problem.
Excuses and apologies, they mean NOTHING. ONLY POSITIVE RESULTS COUNT!
The "end justifies the means!" ALWAYS!