The Woodcraft and CSA pens are NOT the same pen, though they look different.
The biggest difference, other than bushings (which I am not sure about) is the method of holding the center band. WC, Berea, and PSI all three, I believe, requires that you part a tenon all the way to the brass tube.
The CSA requires you part a tenon a certain diameter on the wood/acrylic and glue the center band on.
I personally hate making either pen. Having to make a tenon and glue on the cb for the CSA pen is a pathetic, PITB design. The Berea/WC kits are very troublesome also, and I have had 5 or 6 of them (of the 20 or less I have made) have bad transmissions that retract when you try to write.
If I HAD to make this pen, it would be the CSA pen-- better tranny and a prettier pen IMO. But only if I HAD to.