The cellulose reminds me a lot of an Esterbrook pen, but I've never heard of one that's button filler. No idea.
Fountain Pens
Welcome fountain pen enthusiasts from around the world! Share your fountain pen obsession with fellow enthusiasts. Pens, inks, paper - everything fountain pen related is welcome!
Any idea what the inscription on the nib says ?
I think the big letters say Iridium. But can't really make it out 100%.
no markings on the nib, pen clip, or any of the accent pieces?
Nada
Also, that's not a piston, it's a button filler. It probably doesn't move because the latex sac has completely solidified. A new sac should fix it. It's usually a cheap and easy fix, but I'd send it out if you're not familiar with it. There's a science to sizing and trimming the sac, and you'll need talc and shellac to install it. Also, I find the gold plating on Wearevers to be super thin. So I wouldn't have them buff it.
To me, it looks like some kind of Wearever, but those are typically marked on the clip.
The cap reminds me of the Deluxe 100, and the nib reminds me of this mystery one I'm trying to identify myself.
Upon further investigation, I think it may be a Wearever Pacemaker.