This model has been a personal curse. The first one I bought was lost to history when the envelope arrived open and empty. The second one spent well over a month in customs in San Francisco. I finally got a refund. Eventually it was returned to the seller for having an insufficient address (although it was addressed just fine).
Finally I purchased one originating in the US and it came. Posting pictures to share. It is a very nice writer. Flexible from extra fine to a very nice bold. In person, it is much finer both normal and flexed that it seems in pictures. Beautiful however. It suffers from blobbing as it warms to the hand. I keep a tissue nearby to wipe the pen on as blobs form. But after only a minute to two, it settles down and works as it should.
I filled it via the plug as shown in the ad. It works well that way.
This one is a 4670. There is a mystery imprint as well - "LP - 0"