The Conid CAISO pen is a marvel of precision machining, made as a "passion product" by a medium sized Belgian CNC shop. Fountain pens are a tiny part of their business. The Grimsmo brothers run a much smaller operation but they also make a pen (ballpoint) which counts for a small portion of revenues. There is a tendency for CNC knife makers to also make pens, though few cutlers rise to the challenge of making fountain pens.