Rare Vintage Rotring Radiograph Pen Set

I purchased this high precision technical pen set in 2012 for a special project, and never used it. The set is now a discontinued item, but you can still purchase the individual pens for as much as $33 on Amazon. Replacement nibbes are also still available. Beloved by architects, illustrators, designers, artists, and musicians going back as far as the 1970’s. The set includes 8 steel nibbed pens that deliver constant line widths to exact scale when reproducing your work. Great for drawing on vellum, lineboard, and tracing paper. Pens were shipped with pre-installed ink cartridges, which have dried up due to age. Pens are refillable with Rotring ink. Each pen is a different lineweight. Set includes: - .18 mm - .25 mm - .35 mm - .50 mm - .70 mm - 1.0 mm - 1.4 mm - 2.0 mm - I’m not sure, but this pen could be missing part of the nib? I can’t really tell. Sold as is. Instructions included.