One minor correction on Jim's posts. The ends on the green, blue and red pens are transparent ends from the Levenger Seas pens. The ones I sell will have solid color ends. The orange and ivory pens were made from square rod stock, the ivory is celluloid with the stripes running across the top. Rather nice effect. The clips on both pens were chrome, and have been plated. Marbled finish pens were the Vintage No Nonsense, which came with a gold plated clip.
Richard Binders page on the Connaisseur is worth reading. He has an exploded view showing the parts of a Connaisseur.
Grand Connaisseur pens, and the Royal Salengor bamboo pens used a No Nonsense barrel turned down to fit in the overlay, with the end rings not rings at all, but gold plated discs with the buttons glued on the end.