I have never rebuilt an ignition switch, so I can't speak specifically for that. I did, however, rebuild my OEM dimmer switch when I restored my 1970 Road Runner, and it is still going strong. My dimmer switch really just needed to have the contacts cleaned well. It wasn't made to come apart, but I gently pried up on the metal frame and got it apart.I agree. There are several OEM components on both my cars that either I've rebuilt or had sent out.
In the case of my ignition switch, I had it out last week, tested it for continuity and it was good, but registered what I considered high resistance. Pulled out the lock cylinder and cleaned the bottom of the switch barrel and the lock cylinder contact point, lubed it up with dielectric grease and reinstalled. The Coronet fired right up. Same thing this morning until I got gas, then I had to jump the starter relay. Ran some errands and the engine fired up each time; so there's some random issue going on. Can ignition switches be rebuilt or refurbished?
If it were me, I'd try to fix the original switch - seems you have little to lose!