This is a nib. It’s shiny, but All that glitters ain’t gold*
What am I to say about this . Stub, left foot, good for lefties. more to say on that. Brass finish. Maybe all brass no reaction to a magnet
https://www.gracesguide.co.uk/MacNiven_and_Cameron
* “All that glitters ain’t gold” is a lyric from the Prince song Gold. If you are looking for a rabbit hole ..