Sheaffer Feeds--Ebonite To Plastic Transition?

[stephenchin]

Hey: I was wondering if any of you collectors with the deep Sheaffer knowledge (Dan, Kirch, anyone?) might know then Sheaffer made the transition from ebonite to injection-molded plastic feeds.

 

I have a few of the original No-Nonsense pens with ebonite feeds, which would place production of ebonite feeds as late as 1969-70.

 

But I also have 1970's 330 and 440's that appear to have ebonite feeds as well--graphite grey, with saw marks/machining marks like the mid-60's Imperials. But are they actually injection-molded--and just textured for better ink-flow? I have also seen later, probably 90's quasi-Imperials that have the glossly, deep-black feeds like the later plastic No Nonsense feed.

 

The Sheaffer students pens also make this transition: the flat-bottomed and topped student cartridge pens also use the new-style plastic feeds, similar in design to the No-Nonsense plastic feeds; while the earlier cone- and rounded-end student pens still use the ebonite feeds.

 

So--was Sheaffer still making ebonite feeds into the 80's?

 

This is not an entirely academic question. There are many modern highly-saturated inks with surfactants that I think still flow better with ebonite feeds--but are too saturated or corrosive to use in vintage pens.

 

I'd be grateful if anyone involved in the manufacture, or who has tried to heat-shape or test the later feeds, has the answer. Thanks!