[SEL] A spark plug question from a new member

[Glen Harris]

Hi, all. This is my first post to the list, and I apologize if my 
question is obvious, but I'm totally confused and Google has failed me.

Both my father and I have new (old) Buzacott 3HP engines. His is an 
external tank model in somewhat sparse condition, while mine has a 
hopper with a fair amount of rust.

There's a long way to go before either is anywhere near running 
condition, but one thing we have both done is take the spark plugs out 
and tried to find spares for me and non-rusty ones for him.

Both plugs have a taper thread, and mine measures 0.805" to 0.840" major 
diameter at 14tpi. Dad's plug is marked Edison Albanitum 14-S and mine 
is a Champion A-25. The closest matching thread I can find is NPT 14tpi 
0.840".

I can't find any reference to the Edison plus at all, and the A-25 is 
mentioned to be 1/2" in several on-line references, which is way smaller 
than what I have here.

Can some bright spark please shed some light on these plugs.

Thanks, glen.
(Townsville, Australia)