These were delivered today they are a 7mm kit and the quality is excellent with quite substantial fittings it is the concave pen from Vinny at the turners workshop I have turned these two as per instructions the only thing different to the slimline apart from the shape is you have to press the mechagnisam in quite a long way with only 13/16" sticking out I'm not to sure about the designe so I will be going back out after my tea and make one without the concave enjoy Concava Pen Kit Range - Pen Kits - Shop
This one has a 13mm centre on the concave
This one has a 12mm centre on the concave
This one has a 13mm centre on the concave
This one has a 12mm centre on the concave