Unknown aircraft spark plugs

I found these in my dad's estate. Can anyone tell me if they are aircraft spark plugs and what, if any, demand there may be for them? See attached.

 

Not sure what all used them, but they do have some value. Probably in the 20$ each range if good. From a little info chasing, I would suspect several manufacturers, with engines under 200 hp used them, as I found several ads touting how many hours they could be flown without cleaning.

 

double post

 

You "might" get $1-2 each for them on ebay (maybe $4-5 for the whole lot) which you will likely find to be more effort than it's worth. There's no demand for those plugs because nobody is going to install them in an airworthy aircraft, re: resistor in the barrel. Maybe someone could use them for a museum display. Make a tax deductible donation.
Some of that packaging dates back to the 30's or 40's. Pretty cool for a display or conversation piece. Not much practical use.

Brand new Tempest plugs go for ~$22-$25 each......and they are a superior product.

 

If there is a Part 147 Airframe & Powerplant school nearby I am sure they would be glad to have them.

 

Obvious answer.....

Contact AC and see what they say about them. The data may even be on their website.

 

Bunch of the Frankins and O/IO-470 series Continentals use them. The R-4360 also uses them. I haven't found a Lycoming table yet.