Hi Terry,
I made this one to sell, so I just did it a general size - though it is slightly thicker than some. The difference is usually in the width, although you certainly could draw the 'bulge' down the length a bit.
Yes, people who can use them well really can create some lovely work. I started off trying to learn calligraphy, and in the absence of being able to find a decent oblique pen here, I decided to try and make my own. Now all of my time is spent making pens, and I seem to have no time to learn calligraphy!