Restoring the Guide 6004 Self Canceling switch. I had this switch body painted from before when I did a batch of switches. I recently picked up a parts switch on eBay that had most of the components I needed to make a good switch assembly.
Good cores are getting expensive and even then you're taking a bit of a chance if you don't see inside the switch assembly.
Here is what you will need to do the project, after you have acquired a good core, disassembled , bead blasted, and refinished it. Not shown here also is a surfacing system to deal with the internal switch contacts, which are nearly always in need of attention. Even the NOS switches need to be resurfaced. There being the reason they never got used.It's easy to snap the little retaining tabs off the bulb holder so I keep some push on retainers on hand because it is important to get good ground.
Solder your 3 prong flasher connector on, and don't forget to lubricate all the moving parts in your assembly. Oh, and make sure you get the spring installed in the right position. It only goes on one way. Super glue around the edges of the lens on the inside of the body and hit it with accelerator to set it.
Usually the little grounding clip is missing or broken. I find that using a little piece of sheet metal screw to cut into the paint on the switch body and steering column works well. If it is not grounded, your indicator light will not work.
So this 7 wire system is designed to split the brake lights internally allowing the use of rear brake lights as signal light too.
If you are proficient at these tasks, and set up with the proper equipment, and materials, you should be able to complete the restoration on about 4 to 5 hours.