Deep red Gunne Sax (type) dress

I found this dress and instantly fell in love with it. It is a deep red/pink or slightly maroon. Here is is pictured on my sister who is a true size 12 (it’s not zipped all the way). I would guess it’s more close to a size 8. It is a vintage dress with no tags. I instantly thought it was a Gunne Sax dress when I saw it. I will not be devastated if it does not sell.