Pictures would help but it sounds like you
may have discovered another model there between the VW100 and VW150.
The one thing you have to realize is that the Vantage label was perhaps the most disorganized in the the Matsumoku stable. As you've discovered, several of the members have been driven mildly loony going down the serial and model rabbit hole!

There was also a loose handle on specs and badging so it makes things doubly, um, interesting. The "S" suffix normally refers to "sunburst" so I don't know what it means in your context.
I have the VW150 also from Ontario and it's a super light guitar with a nice projection. Let's have a look at your baby eh?