The grout lines have been painted over with some sort of grout renew.
I have the exact same tub, along with matching pink sink and pink wall mounted toilet.
I would leave the frosted glass partition, otherwise you have to take up the floor.
This 1930s mint bathroom had black velvet wallpaper! The folks over at Retro Renovation would probably see this post and cry.
Is the window frosted to match the glass in the divider? Oh, and it was a windowless bathroom — talk about dark and dreary.
Long term I do wish we could redo the bathroom and make it into more of a small master suite layout.