I've refurbished three pens to very good working conditions with 2556 nibs. Recently though, while trying to correct a problem with a nib the rolled portion broke off -- I now have another nice stub. This was not unexpected because of the wear it already had. So I decided to try the 9XXX series, But I find little and conflicting information regarding the Master Series tip construction and would appreciate assistance. 1 - What did Esterbrook mean when it billed the Master Series as being "tipped with Iridium at the Ball, or wear point?" 2 - Is it just just the tip rolled under and then Iridium welded or a true round Iridium bead on the flat tip end? I would appreciate responses containing profile images - if avail - of 9XXX where the bead/ball is visible. Especially looking for images of 9461, 9555, and 9556, but others would be good for comparison. Tks in advance.......