Good for you. Gunsmithing is one of those dying arts. I enjoy every minute of what I do.
Next project..make yourself a complete set of these in 12,16,20,and 28 ga. They are mechanical dent raisers for shotgun barrels. These will make you MONEY! You only have to make the anvils to fit the tool. Make the tool once and make the anvils interchangable.
Good luck to you!( I have only the 12 so make me a set as well)
Oh and DON'T buy the Wheeler screw driver set. Buy the Brownells set.
If you decide to make these, (and trust me you should) PM me and i will take the tool apart, photograph it and send you the specs. These are $300.00 each if you buy them. The various anvils are $100 ea.