Holy cow .. make me go back into 2008 papers and find this repo from EOVAR.

Says on the bottom .... Published in the interest of those who own and cherish automobiles of a bygone era, by Champion Spark Plug Co, Toledo, Ohio 43661, USA.

Back page bottom Form A-491 (5-74-50)
Under the 3 pages of cars it has a column for old plug number and a 2nd one for new plug number. (seems to be 1974 publication)

Under Billy's cars in DMAC it lists Durant, Star, Loco, Flint, Devaux, Continental 33 /34,

Where Are You From? Ottawa Ont

Do You own a car built by Durant? Dominion built 1932 614 Sedan

Thanks Frank,
Will be in touch later today.
John.

Do You own a car built by Durant? 1929 Rugby d40