I just purchased this pen on Ebay, but am very skeptical that it is a circa 1980s Tombow fountain pen purchased in Japan, which is how the seller described it. It has no branding on it anywhere that I can find. It is rather large, and looks like a cross between a Tombow "Egg" fountain pen and a regular Tombow fountain pen from the same era. (Note photo of mystery pen with a regular Tombow 909 fountain pen laid next to it on the right for comparison.) The pen also has a distinctive middle section with a raised rib pattern. The nib is black and does not look like a Tombow nib. The writing on it says "IRIDIUM" "*ECL*" (the *s represent letters that I cannot read, though it might be "VECLE") and "PEN". The nib has a large flare, but the feed is cut the same as the feed on my Tombow 909. In any case, I'm betting that it is some sort of generic pen from the 1980s, but not a Tombow. If anyone has any thoughts, wild guesses, etc., I would be very grateful to hear them! Thank you.