Do a serious search on the history of Coleman lanterns (or start a collection). It will take you through 2 world wars and bring you alongside the original Harleys and other classic machinery. Do you want to keep fooling yourself and even imagine they used something other than common available fuels? Do you think they used brand specific Coleman? Stop 'fueling' yourself. The older lanterns commonly used regular LEADED gas and somewhat less often, commonly available kerosene.
I don't think you will encounter any problems with switching from/to unleaded gasoline to regular Coleman as long as you don't need to exchange generators such as is needed these days to convert to kerosene.
I can use propane or any of the liquid fuels with my stoves, I wish I could do the same with my lanterns. But I'm still working on it.