I think you are going to find that the majority of the systems still require a key that you switch into an "on" position.
That isn't that alien to me, since I am used to my '40 and '48 Plymouth, both of which came stock with keys and starting buttons. You get in, install they key, switch it to "run" and then push the button. That type of system wouldn't take much to install in either a Gen 1 or Gen 2 it would seem to me.
Im not sure how PATS works, if the key has to be in or not. When we installed systems on newer cars we could tuck a key up in the dash somewhere.
I am just not sure if it will work on a Gen 1 though either. Plus the ones I see on eBay look fugly. I would like to just have a nice chrome button to press, not some huge red "start engine" thing that lights up!![]()