Fixing a large hole between two tiles.

[PipeDownSoldier]

I have a couple of holes where I removed an old thermostatic shower mixer. See pictures. These tiles are not available anymore.

What would be the best way of fixing this?

I'm thinking I have four options:
1. I have salvaged some of these same tiles from a prior job, but they still have the old tile adhesive and mortar on them. I could perhaps try scraping off any residue (is this even possible?) and then re-use them? See pictures for the condition of these salvaged tiles.
2. I have some spare close-matching tiles (but a trained eye would notice they are not original). However, these are 100mm too long and so I will have to cut them down. This will leave an unfinished edge which I'm not too keen about, but maybe I position the cut edge at the bottom?
3. Try to use a straight tile cutter to cut a somewhat circular shape into an offcut of tile and then fix it in place. I can't imagine this will be very easy on a small bit of tile.
4. Leave the tiles in place and just grout over both holes, but that will look a bit crap.

What would you recommend or are there any better options?

Thanks

 

[stevie888]

Do you need a soap dish?

Try soaking the old tiles: some adhesives will certainly soften.

 

[PipeDownSoldier]

Do you need a soap dish?

Try soaking the old tiles: some adhesives will certainly soften.

I'll putting a riser rail over the top of where that hole is, so unfortunately a soap dish isn't possible.

I've tried soaking the tile for a couple of hours in hot water and unfortunately I didn't have much luck with it. It softened a little but it was still not very easy to remove.