I see that shape of neck most often on Italian (not Murano) pieces.
I think is it machine blown as hand / mouth blown would not have given enough pressure to produce mold lines.
I'm wondering if that shape of neck, specifically how it flares towards the rim also has something to do with it being machine made.
I woulds guess that the fine texture came from the mold after which and irridizing salts spray applied and the whole re-heated.
The only thing which baffles me is the sandy looking matte finish on the base and also, it seems on the neck. :roll:
Now I'm wondering it the gather was sprayed before blowing and greater heat and expansion in the centre cleared & iridized the matte look there but didn't do so where there was less expansion at the neck and base.