There is an antique nautical chart that I'll soon be acquiring, depicting the Canadian coast from the Gulf of St. Lawrence through the Strait of Belle Isle. The chart itself is only partial and undated, so I'm seeking to acquire as precise a date and place of origin for it as I can based on the company listed on the chart itself, Gut of Canso & Co.

Here is a link to a hi-res scan of the chart:

http://images.oldcharts.net/gallery/charts/0417-gulfofstlawrence.htm

The vendor of the chart has been unable to provide an exact date of origin, but estimates late 19th century. He also lists the chart-maker as "Imray" (which is a long-established chart publisher based in England).

Based on this information, here's what I've been able to surmise from my own research:

The "Gut of Canso" is a colloquial name for the Strait of Canso, which separates Cape Breton Island from the mainland of Nova Scotia, Canada. This would suggest a Nova Scotia-based company. The term "Gut of Canso" itself didn't really come into common use until around the 1920's (according to Wikipedia), so for it to be the name of a business possibly suggests the chart was produced in the early 20th century.

Imray (full name Imray Laurie Norie & Wilson Ltd.) was formed in 1904 from the amalgamation of three private chart publishing firms. These were "James Imray and Son", "RH Laurie and Sons", and "Norie and Wilson."

There are a number of possibilities here regarding Gut of Canso & Co. - they could have been a subsidiary of one of these companies that later formed into Imray, perhaps the chart was purchased for use by Imray after its formation in 1904 and was reissued, the chart itself actually dating from earlier - or for all I know "Gut of Canso & Co." was a totally unrelated company that paid to have charts issued with its own name printed on them, for its fleet of shipping vessels or something.

Any help, or referrals, would be greatly appreciated. I know this is an obscure request; thanks for taking the time to read!