Girls/boys vintage (brand new) smock/jacket/dress 2/3/4yrs

I will admit I dont really know what this is!! Is it a jacket - YES, Is it a dress - YES, is it a smock - YES, it is unisex - YES...........
Its brand new vintage 70s, 100% thick cotton in a navy blue with red lines. Its has two pockets at the fron, and a zip from the neck to 3/4 of the way down. It is really cute, well made and you decide how to wear it!
For a girl I would pair with a white t-shirt/blouse underneath and red tights and navy patent shoes! For boys  - wear some jeans, t shirt and wear it as a jacket in the autumn/spring.
Chest 24"
Length 18" from shoulder