Have any of you guys ever heard of "Choke Cables" ? Here in Ottawa, most Canadian Tire, Auto centres stock them. They are less expensive than any of the bicycle brake cables, and are available in longer lengths. The choke cables usually have a stainless steel "Wire" in the outer sheath, so it does not rust.
It does help to add a drop of oil to the cable now and then.
I usually use a "Flat angle bracket" at the switch (Point) end of the cable, without the need of any spring. I drill a 1/16th" hole at each extreme end of the bracket, to insert a connecting link to the switch, and the cable. I drill an appropriate hole for a fulcrum screw in the middle corner, and mount it using a wood screw, and an appropriate number of washers, to the wooden roadbed. I use 2x6-8" wooden roadbed for our railway. The points (Switch) is secured to the roadbed also.
There are pictures on the OVGRS web page of our various attempts, at "Inventing" LOW COST, switch controls. WE claim to have invented the original "Patented !! Barrel Bolt switch throw" way back in the 80's...in case anyone is interested.
See them at:
www.ovgrs.org/. The "Track" thread.
The latest method I've been using, is the least expensive, easiest made from CHEAP existing materials, found at your local hardware supplier: the simple, flat angle bracket switch lever.
As far as making springs; all you need is a length of "Piano Wire" (Spring wire), usually available at hobby, and craft stores...even hardware stores on occasion, and a good quality pair of small nosed pliers, along with a pair of side cutter, wire cutters.
It's rather a no-brainer, once a person has an idea of what bends they want to put in that piece of wire !!
The main problem, is usually left in the hands of those that insist in free-floating their switches (Points), and track...how to mount the throws, to their switches.

I hope this helps, or motivates others to make improvements to my, hopefully, helpful suggestions.
Fred Mills