Well I just sold my NOS nosecone and I would have to disagree with you about the factory ones being sloppy. Mine still had very nicely done lead work and the spot welded area under the bumper strip looked very nice also.
I also wonder what these repro guys used for a template. Did they take measurements off an NOS cone? I doubt it, likely got measurements off one 30 year old cone thats been bumped a few times.
I'll take a real cone that needs a little work before I'd take a repro.