Im useless at posting photos.
The bag is made by Prosys. I can find general photos of the bag on the internet, but they dont show the valve in detail and Ive got the feeling that you are in US and may not be able to get hold of products by this manufacturer. This is why I wanted to show you the valve in close up so that you could see if there was anything similar that you could get in US. The one on the left of your photo does indeed look quite similar
It may not work for you anyway, of course. Your OH sounds very determined to fiddle with the valve.
