Generally speaking, NOS parts from that era are going to outlast the chinese junk in the market now. Yes, there were production failures as always but NOS stuff in general is much better. My last issue with aftermarket was a headlight switch. Almost caught my car on fire. I sprang for a NOS one and not only has it lasted years but the dimmer is so smooth versus aftermarket one that was like grinding pebbles. Before that was 11" brake drums from Raybestos that were only $25 each but absolutely unusable and I wasn't going to spend the money on shipping to return to Rockauto. I sprung for NOS and five years later all is well.
Larry, I completely agree with what you are saying but will add my
Companies in China are capable of producing very high quality items whether they be car parts, computers or anything else. 95% of the quality goes back to what specifications they
must meet and what THEY are paid to do so. Our system has driven the manufacturing costs down while padding the executives packages. Little if any of those cost reductions have been passed onto the consumer and we have shuttered our factories in the process.
There is a simple acronym that explains it: CSP, which stands for Cost , Specification(s), Performance. Change any one of the 3 and it affects the other 2. The same applies to any business or product.
So IMO it has little to do with where the product is made but more to do with the specifications it was made to which in turn affects the cost and performance.
When the import tool thing started in the mid to late 70's most of the items were from japan. I have several different items from that period that still function just fine. IMO China is not much different than japan was in the 60's. Continuous improvement until they surpass their competition and they are well on their way of doing so.
So again IMO it's not where it's made but rather the cost and lower specifications they are made to that are set by whom? The corporation buying the components. Our leaders and executives made the decisions to lower the quality in a quest for the almighty $$. It used to be made in the USA stood for unquestioned quality, that slowly slipped to Japan, Japan is now slipping to China.
Why? the answer is in my rambling above
"DEER IN THE HEADLIGHTS LOOK" LOL. 
All I could think was you don't have the normal machine for this?