For GA books it's not too hard to tell, most of the time. They'll say "Printed in Canada" or some such. Also, they'll often be truncated from the U.S. editions...36 pages rather than 52, for instance. Plus different prices.
Truncated versions of US editions are "easy", and you can usually tell a Canadian Timely book because it was distributed by Canadian distributors "SDD" or "CDL". But what about something like:
Milt Gross Funnies #1
Printed In Canada
Publication office: Rotary Litho Co. Ltd., 60 Jarvis Street, Toronto, Canada
Circulation office: Empire State News Co., 77 E. Eagle Street, Buffalo, New York
Distributor: IND (Independent News Co.)
The book was published and printed in Canda, but was using a US distributor. Is this book truly Canadian if the target market was in the US?
And if it is a US book based on the target market then what about:
Strange Mysteries #16
Printed In Canada.
Publication office: 2382 Dundas St. W., Toronto 9, Ontario, Canada
Distributor: ANC (American News Co. Inc.)
Again, published and printed book in Canada but with a US distributor. Should all Superior books be considered "Canadian" or are there Canadian and US versions of Superior books just as there are US and Canadian versions of Timely books?