String tension won't draw the strings in line with the peg hole if the saddle has notches on the top. They won't move the saddle at all since it does not slide from side to side because the ends fit against the sadle slot,
Sorry for the compound quote- but if I sand off one end of the bridge like CTGull suggested, the saddle will be shorter than its slot.
I wouldn't make the saddle shorter, that's not how it's done. You only need to move the strings on top of the saddle and as I said if there are small grooves holding the strings from meeting the bridge pins there are two options. One is if the grooves are not deep you can try to smooth the top, if you take off to much it will lower the action. Two is have a new saddle made. There is a fellow who does this yet you need to send your saddle to him so he can duplicate it. here's his web site.
I've had a local tech notch the saddle to bring the strings closer into line. It's not perfect, but much better. Micheal at Seagull suggested this, saying that a slight angle between the pegs and the saddle is ok. The repairman confirmed that the pegholes were drilled out of line. "Maybe their jig was out of shape that day," he speculated. Maybe so, but the two guitars that show this problem were made in 2001 and 2007.
This Maritime CW GT is turning out to be quite a find! Not only is this the best pickup I've used (better than the Schatten HFM and the Baggs Lyric), it has a wonderful midrange clarity to the acoustic sound. It's not far behind my Tacoma Little Jumbo with the ancient cedar top, a limited edition that listed for $2500 twenty years ago. I hadn't been focused on this Seagull model, but when it came up, I grabbed it. It's taken me a few weeks to understand why that was such a good idea.
I have a 2005 Artist Mosaic Folk and it appears to be well centered.
First, Welcome to the Cabin, hope your stay is long and pleasant.
That's a great guitar you have there, and the folk size is one of my favourite size of guitar. Yep, as you say, from your photo all looks to be well centered, I'm quite sure that most of the guitars manufactured by Seagull will be well centered also, as they are a very good quality manufacturer.