type shape_with_style = {
    sws_fill_styles : shape_fill_style list;
    sws_line_styles : shape_line_style list;
    sws_records : shape_records;
}
type shape = {
    mutable sh_id : int;
    sh_bounds : rect;
    sh_bounds2 : (rect * int) option;
    sh_style : shape_with_style;
}

Should be:

type shape_without_style = {
    sws_line_styles : shape_line_style list;
    sws_records : shape_records;
}
type shape = {
    mutable sh_id : int;
    sh_bounds : rect;
    sh_bounds2 : (rect * int) option;
    sh_style : shape_without_style;
}