The original glow controller was imperfect. It was superceded years ago to a newer part number. To my knowledge, the new part number has not had a single failure. Worth looking into. Why hack up an expensive tractor with a toggle or push button switch when a cheap ($70) controller will fix it once and for all, and with no drilling of new holes or installing out-of-place switches? Besides, by time you spend hours wiring in a switch, then buying the switch, wiring, connectors, the time to run back and forth to the parts store to get that last connector, you can replace the controller in a few minutes and it's fixed.
Had a guy once get mad and said he could put a switch in under the keyswitch in under 5 minutes. I gave him a few tools and said get to it, I'll be back after lunch. 2 hours later he was still working on it. He had the switch in quickly but took a while to wire it properly.
If I'm buying a tractor (and I buy a few), I look at them....just a quick visual. I see a switch installed where it wasn't originally, I'm questioning what was done and how badly was the system(s) hacked up? And what else was done? All this is considered when making an offer and generally speaking...the offer isn't as good as it would be if it was all original, because my buyers are picky. Keep that in mind as well.