At the Boston Pen Show this year, I purchased a substantial personal collection of about 125 vintage pens. Included was a case of Esterbrooks, maybe 30 pens.
Figure I'm sitting around at the Nashua, New Hampshire "Bed and Breakfast" after the show ended, trading pens about with both Richard Binder and Susan Wirth, discussing- go figure- nibs and writing, when I came across one Estie in the case of thirty that had to stay with me a bit, even as Binder conned me out of the other 30, spouting something about "having to have sound basic fountain pens for the website", and "planning t make them write right"... really, i couldn't follow.
But this one...
An Estie 9788 nib, it demonstrated controlled high flex. Magnificent point. And I'm not even so much into flex, though I appreciate the rarity of a high flex in a series not known for it. I've never seen an Estie nib like it, in terms of that flex. Too, it has a breather hole of shape not common to Esties. I'm guessing the teardrop-ish (feel free to chime in with better descriptor) breather hole indicates an early pen?
Anyway, check this thing. The last picture is not with "undue" pressure.
regards
-d