DH worked at an aircraft mfg. plant and they use a Vaseline type lubricant ONLY on plastic gears. I wouldn't use it in any of my vintage machines under any circumstances, even though only 2 get used much. There will never be a unanimous consensus, so just use what you research to be the best for your machines and they way you use them. It will be better than they were when you found them for sure. The old machines are way different than the new ones. Heck, they hadn't even invented sealed bearings in the 1800s and early 1900s. We know the sealed bearings don't last forever either.
To thine own self be true.