I think that if, as Tartan mentions, you pressed the seams to the side, it should be okay. Keep in mind that vintage quilts were hand pieced with a single thread. They stayed together largely because of close quilting, often 2" apart.
The gray fabric isn't a knit, by any chance, is it?
Edit: I could be biased because I don't think it's a big deal to hand stitch an opened seam back together. But I might be in the minority on that.