I picked up a Saito 56 factory control line version.
The CL version is actually easier to do as you don't have to machine the aluminum barrel insert, it already has one you could work with. All you have to do is drill out and tap the one end to 1/4"x20 for the nylon screw, then cut the spigot to the desired length and reduce the diameter near the tip. then just clean, sealed & assemble.
Is there a photo of the C/L version modification somewhere that I can check out? I have a couple of those. Thanks a lot, Dan McEntee