Vintage Black Linen pencil Skirt with Kick Pleat

This is a vintage black linen pencil skirt in blk circa 50s/60s and had very little wear. The only thing is the zipper doesnt fully meet up with the waistline, but this could easily be solved with a hook and eye if it even bothers you. There's no size label as it's so old, it only has the union tag. I'm guessing its a 6.