We can be pretty certain that there are no Chinese knock-off Parker reproductions because when the Chinese make knock-offs, they make a lot of them. And so far, we have seen photographic evidence of exactly ONE Patker repro that has a separated barrel lug.
That tells me some Parker barrel assembly guy in Japan had a bad day roughly 40 years ago.
If there were a lot more, and if this was anything close to a common or widespread problem, we'd be seeing photos of multiple guns with different serial numbers all over the internet.
No matter how good you think Parker repro collectors are at suppressing the evidence of this alleged problem... they aren't that good. But I gotta go because I think I see the ocean rising and the sky falling..
