WTB: Pilot Murex, Eureka Ti Nib FP

Hello,

I'm after a pilot Murex or a Eureka FP. I prefer nails for nibs, and it sounds like these are what I'm after. I'm more active in machined pens, but I'm also open to suggestions if you have one or nib knowledge you'd like to drop to help me dial in my writing instrument. Thanks for your time all.