The comic book connection is modest. Hence, there is not too much investigation into that angle, whether it is in Canada, Belgium, France or Switzerland.
What has attracted a fair amount of attention in Canada are the letters from Vancouver, BC and the Gossett claim that the ransom money is in a bank in BC as well. Galen Cook has done a lot of investigation along those lines.
Also, there are many who feel that DBC might be Canadian based upon his lack of an "accent," and Tom Kaye and other, like Flyjack, have weighed-in on that angle from time-to-time as I recall.
Of course, as usual, I have an ex-wife in British Columbia, so I have extra incentives to keep an eye on what is happening north of da border. Which we can't cross at the moment, btw.
Lastly, for the record, Canada has denied me immigrant status as a Landed Immigrant TWICE! The first time was back in the 60s and the Immigration Officer said, basically, we don't need any more long-haired hippies without any job skills, thank you very much. The second episode occurred 30 years later and centered around the above mentioned ex, as she refused to file the paperwork. The Immigration Officer at THAT time said to me, "Mr. Smith, it is the distinct preference of the Canadian Government that all applications for entry to our country be filed by the Canadian spouse... Um, er... good luck, sir..."
There's always a woman involved isn't there? Can I get an AMEN on that?!