Been needing a letdown tool but couldn’t see paying what the store bought ones cost. Got to thinking about the way the Joe Collins handled the problem with his mainspring winder and decided that the same solution could be applied to a letdown tool.
Dug around in the junk tools box and found another (cheap version of the) Hanson/Irwin tap wrench. Cut a piece off of a broken post hole digger handle, turned it down in the lathe, and drilled a hole in one end for the tap wrench to fit in. Removed the slide handle from the tap wrench and cut off a piece of it long enough to fit through the wood handle. Measured the wood to locate where the hole in the tap wrench would be and drilled a hole in the wood. Seated the tap wrench in the wood with a couple of hammer blows and drove the cut off piece through both the wood and tap wrench which locked it in place nicely. Found a large brass bushing from the brass junk box that would fit the handle to use as a ferrule, drove it on over the locking pin and turned it down to fit. Sanded the handle down a bit and now have an adjustable letdown tool.
Pictures of the finished piece below. Realized after finishing it that I should have taken pictures of the process but was a bit too late.