It's a 90's Montblanc 146 "Legrand."
1 - Tier 1
4 - Fountain pen
6 - Nib size of 6
I purchased this pen from limitlesspens in Austria off of fpn.
Has a pretty rare 18k two tone gold nib.
It is/was a working everyday pen so it does have some scratches, and part of the finish is wearing off on a section of the cap band, and the cap was replaced a while back.
It writes beautifully. This is one of the last few years of the brass piston, and it is nice to use. Striped ink window.
I can send detailed pics of whatever you want, just im me your email.
$250 shipped.
ETA: There's no corrosion on the nib, I had just finished inking the pen haha