Tony
I'm a FP user and I've made a number for myself and friends.
Two things to be aware of. First, there are two distinctly different designs for FPs - those that use a 'snap cap' to hold the cap in place, and those where the cap screws onto the body. As an FP user, I prefer screw caps - the snap cap design allows the feed to dry out more quickly which means that if you don't use a pen for a few days, it might not write immediately when you do start using it.
And as a pen turner, I find the snap caps to be a nuisance to assemble. You have to screw a small, untapped piece of plastic onto a threaded stud under the cap finial - the instructions tell you to insert a special tool (or a No 2 Phillips screwdriver) into the cap to screw it in place, but my experience is that that approach doesn't work very well. I've found that its easier to thread the plastic cap first using a metric tap, but then there is the issue that if the plastic is threaded, it will too easily unscrew from that stud, so you then have to apply a small drop of thick CA to the threads before assembly. And I've also had the unfortunate experience of having the plastic snap cap break - which really complicates things if you are only doing one or two pens.
The second issue is that all FP kits require at least a 10mm drill, and often something quite a bit larger. 10mm is fine, but I can't justify the cost of a special set of drill bits for the larger kits, so I've stayed with 10mm kits. Unfortunately, the selection of 10mm kits is very limited (mostly snap caps).
