Hi Bill, hey, nice drawing! You know, it's funny how certain things just may not occur to you until someone else says something to jar you. I hadn't considered any way of attaching the throw wire to the bar below other than solder. Now, your idea of a press fit and cement got me thinking. I am not mechanically inclined, so please forgive me if I say something stupid, or unworkable. My first thought was what kind of cement would be used and I suppose 5 minute epoxy? Then I thought the problem would be not being able to disassemble for point service. I've learned over the years that being able to take things apart even when you see no reason why you'll want to do so is a good idea. When you wrote about turning down the wire to solder the tip in the rail, my first thought was " I can't turn it down, I have no such equipment or knowledge" Later, I thought that if you are going to turn something down, why not use a small diameter brass threaded rod? solder to the rail the same way, but use nuts to fasten to the rod below. To avoid turning down the threaded rod, perhaps a hole could be drilled in its end, and a very short piece of .031 wire soldered in.
In my original thinking, I was going to try the largest wire that could be accomodated in the rail and check its performance. Of course I hoped it would work fine , end of problem. If it flexed too much, I hoped there would be telescoping brass rod available. Then I could solder the wire to the rod, and the rod would not flex. Come to think of it, if brass rod could be used, the bottom end could be threaded and a screw driven in, preventing the throwbar from falling off. The lighter the throwbar the better, because its weight will be hanging on the solder joint of wire to rail. It's pretty much a matter of seeing what size wires and rod are available, I haven't checked.