Posted By:
MillerhouseKeith,
Check out Burdick's original ACC catalogs. Nineteenth Century tobacco listings were given numbers only: #28, #29, #167, #172, etc. "N" listings were for South American sets or something equally unusual.
I'm not sure which resource first started applying "N"s to 19th Century tobacco, but it didn't occur until the 1970s, as I recall. Unfortunately, as I write this at work, I don't have my old reference works at hand to check where it first appeared. If I had to guess, I'd guess Bert Randolph Sugar did so in his old Sports Collectors Bibles.
Regards,
Dan Gantt