You're right! I forgot you already experienced Japanese pens. Sorry, I don't remember everything, I must be getting old! Sailor is definitely a little different. There's a slight scratchy texture to Sailors which I sometimes like and I sometimes don't like. The Sailor is definitely different!
The Namiki factory is mainly focused on the Maki-E and urushi. From what I gathered in my tour, tour was a one-on-one tour with a Japanese speaking docent and my Japanese is quite bad, so speaking about precise details was difficult. From what I gathered, the fountain pen nib is made in a Pilot factory, but the nib and feed are assembled at the Namiki factory (which makes sense since Namiki uses different feeds than Pilot). The Pilot Urushi and Maki-E pens are also made at the Namiki factory. The Chinkin pens are first urushi pens from the Namiki factory and then they go to the area near the Noto Peninsula (where the earthquake was on 01-Jan-2024) area where the Chinkin artist resides. Namiki doesn't seem to have an actual factory there, but the Chinkin pens are not made in the Namiki factory, from what I gathered.