That is a hard one with those tiles. I would have to think if you did a white, it would kind of work with the colour of your tiles. At the end of the day, they do need to be replaces, but as you said, due to budgeting reasons, you cannot, I can pass on this photo of a nice bathroom with those tiles for you though for inspiration... : )

I really like that floor. I hope you are able to keep it once the complexities of waterproofing are revealed. Really large tiles would not be era appropriate. And they were moving away from subway tiles by then. Perhaps 20-25cm square in running bond for that decade? Colour will be easier to pick when the green is gone. I think bright whites could be useful accents but were not really available back then, except whitewash. So depends on how true to the age you want to be or if you’d prefer to have your own blend of the best of two eras.

Yes, siriuskey. You are right again. It would be smart to invest in having a professional draftsman draw it up. But on face value, I really think oklouise's plan works. I have sort of drawn it out on the floor. I love that she is using standard size vanities with only a custom made top, and the towel shelves are now 450 instead of 250 wide, which is much better. The little odd-shaped infill at the end of the bath provides a spot for the lovely jug and bowl set my mother made for me. (I used to use the jug to pour water over the grandchildren's heads when I washed their hair, and now it's just a lovely decorative item with deep sentimental value) and there is space beside the bath for the urn filled with decorative soaps that was a gift from a son-in-law on his first visit to our home. I really think the bath needs to come back to 1500 long, but that's not an issue at all. I found a really nice shaped oval tub at 1500 x 760 that I like and is quite inexpensive. I don't need to worry about towel rails because I have a lovely timber free-standing towel rack that will fit nicely at the end of the shower if the shower door is placed on the side. It looks like the vanity drain can run under the drawers and into the bath outlet and the WC vanity will run under the wall into the shower drain, and all other plumbing stays the same except I'll ask the plumber to chase the shower tap and rose into the exterior wall rather than have it on the side, OR there is room for a false wall in front of the exterior wall to hide the plumbing if that works out better. The niche can go in the new wall behind the WC vanity. I'll be really surprised if this isn't a feasible plan, but I will take your advice, siriuskey, and get a pro to draw it up so I can be totally confident it works. Can't thank you enough, oklouise - and you, siriuskey, for all your efforts which, I think, contributed by generating new ideas and flushing out the important issues.

@dreamer I don't have measurements as we're not in the house yet... but attached is a picture of the bathroom. House is on concrete slab and brick veneer, so I imagine a bit more work would be required to remove and fill in said window? @Gianna Bruschi I might just suck it up and live with the current layout and a little refresh. We are only in this property for 6 years. Too long for me to want to live with a green bathroom and not long enough to invest too much. That's where my dilemma is.