One of my favorite fountain pens is a franken-pen i built myself. Vintage pens have wonderful nibs but i find the bodies to be ugly or at the very least functionally limited. So i decided to take the best of both worlds.
This is my TWSBI Diamond but with the stock nib replaced with a 1910 flexible nib from a Waterman 52 (an ideal #2 nib), extra fine. I also replaced the feed with a ebonite feed so it has absolutely no problem keeping up.
In my mind this is the penultimate pen in everyway.