[AT] old spark plugs

[Ralph Goff]

Since we have been talking spark plugs I wonder if anybody can identify some old ones I have here. I'm guessing they came from my grandfather's McCormick Deering 15-30 tractor since that was the first engine on the farm. The only one older would be the IHC Famous 20 hp single cylinder stationary engine and I have no idea if that even had a spark plug. The list of spark plugs is as follows:
AC 77, this is a dual electrode and a big plug that takes a 15/16 socket as do most of them. 
AC 75 Com
AC E9
Champion 1Com
Champion C4
Champion 15A which a smaller plug taking a 7/8 socket. 
The Champions are not "new in box" but slightly used in box. Wonder if they are worth anything to collectors?

Ralph in Sask. 
Champion 1 Com