Switches and relays use the following industry terms to describe the contact arrangements, so that you don't get all involved (or confused) when trying to type or say what you want.
Form A = make = normally open. (A as in mAke)
Form B = break = normally closed (B as in Break)
Form C = make/break = one make, one break = transfer (what the general public calls a SPDT) (C as in Combination)
So, a DPST would be called a "2 Form A" and a DPDT would be called a "2 Form C"
Most Radio Shack illuminated switches are "single Form A" designed to be used in automobiles, with 12 volt systems. This will be a problem if you try to use them for track indicators. They will burn out rapidly, or instantly, depending upon the voltage you apply to the track. A better way is to use separate switches and pilot lamps for each circuit. In that way, you can use switches with 2 Form A contacts. One set of contacts powers the rails, and the other set powers the pilot, using a separate, constant voltage that is compatible with the pilot lamp. (the nice thing about this scheme is that you can dim all the pilots during night-time running sessions.)
Track switches will require switches with 2 momentary Form A contacts. See the diagram to learn how to wire the pilots, but note that there is a series wiring scheme going on, such that the pilots are in series with the coils. You might want to save the hassle and just use the conventional switch controllers. They look nice and have the pilots already installed.
The first inclination of people when they want to slow something down or reduce the voltage to an accessory is to ask about resistors or rheostats or potentiometers. Resistors reduce current, not voltage. Russell is absolutely correct when he recommends using diodes to lower the voltage to the sawmill. Before you use the diode method, though, have you considered using a different transformer tap, with lower output voltage, or a separate small transformer, dedicated just to accessories and set to just the right voltage?
