If a friend in your situation was to ask my opinion after reading this forum for more than 2 years I would say when in doubt don't. I doubt that the next p380 will come in the unacceptable condition as your first one but when I read of multiple issues with a particular gun I stay away from that model no matter how much I think I wanted it. Just my opinion on your question. By the way I have a mk9 & mk40 & think they are well made. I also don't like plastic from any gun manufacturer.
Both my PM9 and P380 were in perfect condition but my LGS had them in stock so I was able to inspect each one before buying. I would have passed if they put that in front of me too.
I agree with the boys on this one. I will add that the take down pin spring on my new CW380 is coated yellow. I found that a little odd but it doesn't seem to effect anything.
What was the Serial Number on this P380? It looks like RD3167 but it's hard to tell for sure on my phone.
My Serial is @ 250 units away from this, and my box also had a Kahr #30 inspection tag just like this one. Not very comforting.