Old-style M600?

[AzJon]

So I picked up what I thought was a black M400. To my surprise it has a monotone 18k nib! Looking around, it appears to be an early old style M600!

https://i.imgur.com/CO7ssSn.jpg?1

https://i.imgur.com/nq6IxWb.jpg?1

It also has an interesting stamp on the side that looks like an E and an N with a line between them. Any insights there?

https://i.imgur.com/ZUDZRzR.jpg

Either way a pretty cool find and the nib is excellent. Very pleased.

[carlos.q]

I have one of these old-style M600 pens and it's one of my favorites. The nib is a real joy.

For more info on the E/N markings you can start here:
https://thepelikansperch.com/2014/09/22/the-pf-pn-nibs-explained/#more-783

[AzJon]

All that information would seem right. As far as I can tell this is from 1985-88 with the single tone nib. Interesting about the EN being for the French market (on a pen that found its way to America).

Interesting that all of his examples are the two-tone nibs. Mine is definitely an older monotone nib:

https://i.imgur.com/UyMAVrx.jpg