From WoodworkersZone WoodWiki
There is a growing trend among pen turners to step beyond the kits available from distributors, into the realm of kitless or heavily modified pens. We will leave the argument about how much of a kit can be used in a kitless pen to those who seem more interested in semantics than making pens. An important contributing factor that allows us to modify the Cigar kit is that its tubes are a slip fit into the single tube for the Sierra (Woodcraft's Wall Street II). The kits are all available from Berea and that company's vendors. There are tutorials elsewhere that address the solid body pen, but our purpose here is to take the single-body conversion one step further and make it a click pen.
This article is a work in progress. Please save your comments until it's finished.