Here's a link to some speculation on Harmony Central:
Here's a picture of the guitar that is advertised on Craigslist. I think it is priced at $100, which is a decent price if it is in good shape.
I have owned my Seagull for 20 years and when I first bought it I did a little research on the company and found almost nothing, but I recall they were using "La Si Do" as the corporate name and I am pretty sure they had a line called Minstrel. I may have to post on the main AG site to pose this question to a wider audience.
Here's an AG thread from 2008 on this topic
Today I had an opportunity to visit the store that had advertised the Minstrel guitar on Craigslist. It was definitely made by Godin / La Si Do. The serial number was 5xxx. The guitar was clearly made for an entry level player. I think it may have been made entirely of wild cherry. I didn't try to play it. I think it would have taken a fair amount of work to get it into proper playing form. The finish was flat and quite thin. I have seen a lot of Godin guitars over the years, and this one was not up to the level of any of the others. Of course, there may be some terrific examples out there, but this one was old and needed some TLC.