Vintage 80s dress size Large

Vintage 80s dress. Made in Canada. Labelled size 15/16. Pit to pit approximately 20” and waist 15”. Length from waist to hem at front 27”. Black sheer fabric with fun pattern in primary colours. Elastic waist with removable belt. Button puff sleeves. This dress is sheer. Would need to be worn with a slip, I imagine it originally had a slip lining. See photos for condition and details.