While it will need to be treated with care, I think you are ok, the edges seem to be very nice and stable without a lot of ravelling.
Back in the day when/before I started, very little was said about seam allowance. Mostly they were eyeballed, you had a template that was the size of the piece you wanted and you rough cut the seams around your drawn lines, or you cut the pieces with whatever seam you chose and eyeballed the seam.
I remember looking for guidance and not finding much -- I remember one book did say that depending on the fineness of weave of the fabric, quilts could be made with down to 1/16th!! I don't come from a quilting background/family and I used 1/2" seam allowance until I got my first rotary ruler in the 80s. 1/4" just seemed so impossibly small coming from clothing and 7/8ths.