Integrate Custom Post Type with an ecommerce (Woocommerce o others) - WORDPRESS
I was also in the same situation and managed to make a solution.I made it into a plugin. You can download it here http://reigelgallarde.me/product/woocommerce-woorei-shop-manager/. Just read the discription for instructions.
I would also like some feedback cause there might be some faulty functionality that I overlooked.
Looks like your best bet is this plugin right here: https://wordpress.org/plugins/post-type-switcher/